Psiphon, an Internet censorship evading software project developed by the University of Toronto’s Citizen Lab has been deemed “the world’s most original, significant and exemplary Net and Digital Initiative” by a panel of French and international government, media and business experts. Psiphon was chosen first among 100 technology projects from around the world that were nominated for the Netxplorateur of the Year Grand Prix award.

Plans to tear down the so-called Great Firewall of China were being debated and a decision was expected soon, said Wang Hui, head of media relations for the organising committee…

“I believe you will be able to (access banned sites such as the BBC) but I can’t give you a promise yet. The relevant government departments are still working on it,” she said.

That’s something to keep an eye on for sure.

An article in The Guardian discusses the rapid growth of Internet usage in China the related effects. The article discusses how the Internet, and blogs in particular, have created “competing public opinions.” This is an interesting way to frame the topic as censorship in China is often characterized as monolithic when in fact there is a significant amount of competition in the realm of ideas. Even within a confined informational space there is considerable movement — what I’ve called wiggle room in the past — if one looks for it.

However, the article repeats the charge that China is exporting their Internet censorship technology:

Campaigners suspect China is passing its censorship know-how to Cuba, Vietnam and several African countries.

Now, I don’t doubt that others are looking at the forms of control China is applying to the Internet and evaluating how they too can keep the benefits, particularly economic, that come with the Internet while minimizing its use for free expression but I’m not so sure that this means that China is actively exporting censorship technology. As it currently stands, ONI found no filtering in Zimbabwe despite reports to the contrary. While Vietnam does censor the Internet it does so in a very different way than China does. Cuba may conduct a limited amount of filtering, but it is also much different than that in China. RSF reported:

There is hardly any censorship of the Internet in Internet cafes. Tests carried out by Reporters Without Borders showed that most Cuban opposition websites and the sites of international human rights organisations can be accessed using the “international” network. In China, filtering for key-words makes it impossible to access webpages containing “subversive” words. But, by testing a series of banned terms in Internet cafes, Reporters Without Borders was able to established that no such filtering system has been installed in Cuba.

While not ruling out the possibility, I am skeptical of this claim based on my experience with testing filtering systems in these countries. (What’s more interesting is that Comcast’s filtering in the USA is more like the GFW than any of these countries.)

The New York Times published an article that looks at the resistance to Internet censorship in China. It picks up on the theme of backlash that I’ve suggested comes about when over blocking occurs. When common web sites and services are blocked, it helps turn normally apolitical people into activists. The NYT reports:

For a vast majority of Internet users, censorship still does not appear to be much of a factor. The most popular Web applications here are games and messaging services, and the most visited Internet sites focus on everyday subjects like entertainment news and sports. Many, in fact, seem only vaguely aware that China’s Internet universe is carefully pruned, and even among those who know, a majority hardly seems to care.

But growing numbers of others are becoming increasingly resentful of restrictions on a wide range of Web sites, including Flickr, YouTube, Wikipedia, MySpace (sometimes), Blogspot and many other sites that the public sees as sources of harmless diversion or information. The mounting resentment has inspired a wave of increasingly determined social resistance of a kind that is uncommon in China.

The Financial Times reports that Guo Quan, a Chinese scholar, is planning to sue Google because a search for his name in google.cn is censored. If some one gives me the proper Chinese translation for his name I can check this out further. (In English it returns results, using 郭泉 results are also returned along with Google’s standard censorship notification. The name itself is a censored term as a search for it with a non-existent domain will produce the censorship notification as well. Yahoo.cn and Baidu produce no results. They will produce results if something is appended to the search (yahoo.cn, baidu)

The Atlantic published an article on censorship in China (it seems to be gone now, here are links to Google’s cache: 1, 2, 3, 4) that takes on the challenge of explaining the technical measures used to censor the Internet. The article also discusses circumvention and the self-censorship component that is so integral. The article concludes with some salient points regarding the important role of domestic censorship as well as the widening space for dialog:

It would be wrong to portray China as a tightly buttoned mind-control state. It is too wide-open in too many ways for that. “Most people in China feel freer than any Chinese people have been in the country’s history, ever,” a Chinese software engineer who earned a doctorate in the United States told me. “There has never been a space for any kind of discussion before, and the government is clever about continuing to expand space for anything that doesn’t threaten its survival.” But it would also be wrong to ignore the cumulative effect of topics people are not allowed to discuss.

However, the are several issues with the technical analysis as well as underlying tones of “exceptionlism” that obscure some of the bigger picture issues.There seems to be confusion over surveillance and filtering. Its best to think of filtering a set of rules, if packets contain something that violates the rules certain actions are taken. If a destination IP address is on a block list, the connection is not made, if packets contain certain keywords reset packets are sent to the source and destination to terminate the connection. Surveillance implies that someone is watching the traffic, or more logically it is stored, parsed and then someone looks at it. When surveillance and filtering are (con)fused together you get something strange like this:

Thus Chinese authorities can easily do something that would be harder in most developed countries: physically monitor all traffic into or out of the country. They do so by installing at each of these few “international gateways” a device called a “tapper” or “network sniffer,” which can mirror every packet of data going in or out. This involves mirroring in both a figurative and a literal sense. “Mirroring” is the term for normal copying or backup operations, and in this case real though extremely small mirrors are employed. Information travels along fiber-optic cables as little pulses of light, and as these travel through the Chinese gateway routers, numerous tiny mirrors bounce reflections of them to a separate set of “Golden Shield” computers.Here the term’s creepiness is appropriate. As the other routers and servers (short for file servers, which are essentially very large-capacity computers) that make up the Internet do their best to get the packet where it’s supposed to go, China’s own surveillance computers are looking over the same information to see whether it should be stopped.

If one conducts passive surveillance with a tap, one cannot then go back and interfere with the packets. For filtering, such a setup is not needed. You just route the traffic though something that filters — basically all routers can filter. The filter looks at the packets and matches them to the rules. There are no “tiny mirror” or whatever. If you want to conduct passive surveillance you can use a tap and record the traffic for analysis. The two things are not really related. Moreover, internet surveillance is not something that only China does or that is easier for China to do — a quick look at the most sophisticated internet surveillance system in world can demonstrate that.

On to the mechanisms:

DNS tampering is explained well (although there may be some new variant). An important point is that most ISPs have their own DNS servers, managing a centralized system could be awkward (though not impossible), and users can use other uncensored DNS servers.

IP Blocking: This technique is incorrectly explained in the article.

While your signal is going out, and as the other system is sending a reply, the surveillance computers within China are looking over your request, which has been mirrored to them. They quickly check a list of forbidden IP sites. If you’re trying to reach one on that blacklist, the Chinese international-gateway servers will interrupt the transmission by sending an Internet “Reset” command both to your computer and to the one you’re trying to reach.

If packets are sent (trying to establich a tcp connection) for a particular IP and they pass through a router configured to block packets for that IP, the router will block those packets. Thats it. There is no connection ever made. If you sniff such a connection you will only see outgoing syn packets and nothing else. No reset packets are sent. There’s no “mirror” processing anything while you wait.

URL keyword block – This technique is actually the resest one described under IP blocking. If any part of the get request contains certain keywords — and domain names are often used as keywords — a reset packets will be sent to both the source and destination to terminate the connection. When is it triggered? This is confusing because the GFW’s keyword filtering is bi-directional but in my experience it is triggered on the way out of China. I say this because you can trigger it by requesting non-existent content. Depending on how long it takes to send the reset packet you may receive some of the content you requested which is what makes it appear that the filtering happens on the way in. After receiving reset packets the source and destination will not be able to connect to each other for a period of time.

Body Filtering – This is a bit of a tough one. Basically, if you create a web page with a keyword that normally triggers the reset packets if it appears in the url path, you can access it fine from China. I originally thought that this meant that body content was not filtered, but if you create a large page of such words the reset packets can be triggered. This may mean that a sampling of packet are checked, not all packets. In any case the behavior is the same as discussed above — the source and destination cannot connect to one another for a period of time. If you keep requesting the content you trigger more reset packets so t takes longer to be able to connect, but if you wait, and then trigger the reset packets again it won’t be longer the second or third time. There’s no escalating punishment.

Bi-directional keyword filtering

As Chinese-speaking people outside the country, perhaps academics or exiled dissidents, look for data on Chinese sites—say, public-health figures or news about a local protest—the GFW computers can monitor what they’re asking for and censor what they find.

Again, the keyword filtering is bi-directional, if you trigger it on connections to China the same behavior applies. Again, the issue of “monitoring” in this context implies that there’s something intelligent and deliberate about the filtering. If the packet matches the rules, it triggers the filtering mechanism, in this case reset packets.

Circumvention

Easy is a relative concept here. If a user chooses to break the law and acquires the necessary knowledge to by pass censorship then, yeah, it can be easy. You can buy vpn access — at least until lots of people start using and then it gets blocked – or use an encrypted proxy — at least until it gets blocked. They don’t need to block all VPNs, they can just block the IP addresses of those they want — those that become popular amongst citizens seeking to circumvent the GFW.

But despite the issues with the technical mechanisms the article is dead on with its conclusions:

What the government cares about is making the quest for information just enough of a nuisance that people generally won’t bother. Most Chinese people, like most Americans, are interested mainly in their own country. All around them is more information about China and things Chinese than they could possibly take in… When this much is available inside the Great Firewall, why go to the expense and bother, or incur the possible risk, of trying to look outside?

All the technology employed by the Golden Shield, all the marvelous mirrors that help build the Great Firewall—these and other modern achievements matter mainly for an old-fashioned and pre-technological reason. By making the search for external information a nuisance, they drive Chinese people back to an environment in which familiar tools of social control come into play.

Ding! We have a winner.

Battles are being fought all over the globe, while the development and use of technologies that protect privacy and make it possible to circumvent censorship are rapidly increasing. The same tools helping dissidents to evade censorship in repressive countries are also being used by citizens in democratic countries-to protect themselves from unwarranted Internet surveillance. Focusing on the global character of both the practice of Internet censorship and surveillance, as well as the resistance to it, provides for both a better understanding of this important trend as well as for the possibility of creating global alliances to combat its spread.

The full article is available below.

Evasion tactics: Global online censorship is growing, but so are the means to challenge it and protect privacy Index on Censorship, Volume 36, Issue 4 November 2007 , pages 71 – 85 (pdf)

The number of countries that censor and monitor their citizens’ use of the Internet is increasing. While it is no secret that China and Iran censor the Internet, at least 25 countries, including Pakistan, Ethiopia, Thailand and Uzbekistan, also have technical filtering regimes in place. Some of the technology is even exported by western companies: search engines, blog hosting providers and email providers have extended their existing filtering mechanisms-which usually target pornography and copyright infringement-to censor political content and gain access to lucrative markets in repressive countries.

Censorship and surveillance is not restricted to authoritarian regimes. The technology used to censor the Internet in entire countries in the Middle East and North Africa also filters access in schools and libraries in North America. An Internet service provider (ISP) in Canada blocked access to a website set up by members of its workers’ union during a labour dispute. ISPs in the United States have implemented a sophisticated, and illegal, monitoring and data-mining programme, covering both Internet and telephone communications, at the behest of the National Security Agency. The problem is magnified when the concept of censorship is extended beyond just the technical aspects of filtering web content and Internet services.

There is, however, a growing resistance to Internet censorship and surveillance, although it is often characterised as a struggle confined to dissidents in a few select authoritarian regimes. There are a wide variety of awareness raising campaigns as well as academic research projects aimed at exposing and confronting censorship. Legal battles are being fought all over the globe, while the development and use of technologies that protect privacy and make it possible to circumvent censorship are rapidly increasing. The same tools helping dissidents to evade censorship in repressive countries are also being used by citizens in democratic countries-to protect themselves from unwarranted Internet surveillance.

There are three key factors to Internet censorship. First, there are formal and informal mechanisms, including laws, licensing and self-regulation, that act to create the legal, and often extra-legal, framework within which Internet censorship takes place. Second, there are a variety of technical methods through which Internet filtering and blocking can be implemented to restrict access to content and services online. Third, Internet surveillance technologies are routinely deployed in order to monitor and track online communications. All countries use varying degrees of these to implement control, generating fear among Internet users and contributing to a climate of self-censorship that is creating alarming challenges to freedom of expression online.

The legal basis for technical filtering is murky and rarely explicit, and can vary significantly from country to country. It is often a combination of press law, telecommunications regulations and laws protecting state security. Regulation and oversight is most often conducted by the Telecommunication Ministry or by the often state-controlled telecommunications companies.

In South Korea, the Ministry of Information and Communication instructed Internet service providers to block access to content deemed to be ‘North Korean propaganda’ and thus illegal under the vague, and often abused, national security law. The Korean Internet Safety Commission (KISCOM) has also been set up to advise the government’s Internet censorship policies and its logo is prominently featured, along with the National Police Agency’s logo, on the ‘block page’ users see when they try to access censored websites. South Korea received a ‘high’ transparency rating from the OpenNet Initiative-a research project documenting Internet censorship. This was based on the country’s open acknowledgment of filtering, along with the presence of a ‘block page’ that informs users when attempts are made to access censored content.

In contrast, Uzbekistan received a ‘low’ transparency rating because the country’s filtering regime is based on a combination of self-censorship by ISPs and pressure from the country’s intelligence service-the National Security Service (SNB). In addition to occasionally ordering ISPs to block specific sites, the SNB monitoring also encourages them to self-censor or risk having their licences revoked. In a way, the practice is symbolic of the censorship regime as a whole. The ISPs attempt to conceal their filtering by redirecting users to innocuous sites when they try to access blocked content.

In some countries, there is no technical filtering in place; it is the legal system itself which acts as the primary mechanism of Internet censorship. Threatening ISPs, or content providers such as search engines, with ‘takedown’ requests is one of the most undocumented methods of censoring Internet content. In some cases these can be formal legal requests for removal due to copyright violation or claims of libel/defamation or informal requests due to allegations of supporting terrorism. ISPs are not required to report such ‘takedowns’ and most happen in complete silence. In these cases, ISPs act as judge, jury and enforcer at the same time and will act to remove content rather than fully investigate the claim, in order to avoid liability.

The questions surrounding the lack of transparency and accountability led Christian Ahlert, Chris Marsden and Chester Yung, from the Oxford Centre for Socio-Legal Studies, to investigate what they termed the ‘privatisation of censorship’. In 2003, they conducted an experiment, known as ‘Liberty’, to test notice and takedown procedures in the US and Europe. They created a web page containing text that was clearly in the public domain and uploaded it to ISPs in the US and the UK. The uploaded text was an excerpt from Chapter 2 of J S Mill’s On Liberty, which discusses freedom of the press and censorship. They then created an email account with a free service for a mythical organisation called the ‘John Stuart Mill Heritage Foundation’ and sent takedown notices to the ISPs claiming copyright infringement. In the UK, ISPs took the information down, but in the US, they asked for more details, including a declaration ‘under penalty of perjury’ that the claim was valid. At this point, the researchers terminated the experiment. However, they noted that if they had supplied the language required by the ISPs, the takedown process could have continued.

In 2004, the group ‘Bits of Freedom’ conducted a similar experiment using Dutch ISPs. They uploaded text that was clearly in the public domain-the text even stated that it was in the public domain-and then sent takedown notices from free email accounts. Of the ten ISPs tested, only three did not remove the content. One provider even forwarded the account details of the customer to the complainant. ‘Bits of Freedom’ went further than the ‘Liberty’ experiment by filling out a form sent by the ISPs that asked for additional details including name and address and to ‘indemnify the provider from any liability for acting upon the request to take down’. This led ‘Bits of Freedom’ to conclude that the ‘penalty of perjury’ test which worked in the ‘Liberty’ experiment was clearly not enough of a check against abuse.

These studies exposed the flawed process through which takedown and notice are being implemented. It is clearly being exploited to silence online critics. The Church of Scientology has used takedown notices alleging copyright violations with great success, even forcing Google to remove links from its search engine to particular sites. In addition to copyright, threats of law suits for defamation and libel are increasingly being used to stifle criticism. Singapore and Malaysia have often been accused of using such tactics. The new targets for libel and defamation cases are bloggers. While many blogs are about personal interests and read more like a diary, the blogging platform is also being used by citizen journalists, who publish without the filters of the traditional media.

While there have been documented cases where bloggers have been prosecuted for libel or defamation, many never make it to court. In August 2007, the website of the Iranian blogger Hossein Derakhshan was shut down. Derakhshan’s blog has long been censored in Iran. Despite being filtered, it remained popular and Iranians used technology to bypass the filters and access the site. However, after criticising an Iranian intellectual, Mehdi Khalaji, for working for a conservative think-tank in Washington DC, Derakhshan, his web hosting company, Hosting Matters, and domain registrar, GoDaddy, were served with a takedown notice. The notice, alleging libel and defamation, led to the deletion of some of Derakhshan’s blog posts by his hosting company and ultimately to the termination of his blog’s hosting service. Exemplifying just how flawed the notice and takedown process is, the notice claimed that in addition to Derakhshan, both the domain registrar and the web hosting company were implicated in and/or liable for activities conducted on Derakhshan’s blog. The notice implied that each of the three named in the notice (the registrar, the hosting company and Derakhshan) ‘published’ defamatory information and were therefore liable for damages.

The chilling effect of notice and takedown is well illustrated in this case. Faced with legal threats, Derakshan’s web-hosting company ordered him to remove ‘all’ references to Mr Khalaji or they would remove his entire website, even though the company recognised that the claims fell into a ‘grey area’. After taking down the offending posts, but refusing to remove all references to Mr Khalaji, Hosting Matters asked Mr Derakhshan to remove additional posts about Mr Khalaji.

Please remove the latest post you have made referencing Mehdi Khalaji. This person continues to insist that everything and anything you post about him is defamatory. While we do not agree with the assessment as it relates to the latest post you have made, we do not have the time, interest, or resources to invest in continually dealing with his complaints and to review your site.

(Source: http://hodertemp.blogspot.com/2007/08
/accounts-and-billing-hosting-matters.html)

This exchange clearly shows why ISPs are not equipped or qualified to make judgments on content and will always default to the lowest common denominator, with serious repercussions for freedom of speech and expression.

Content removed for allegedly supporting terrorism is one of the least documented forms of takedown. With copyright and defamation there is at least some element of a legal procedure, however flawed, but when it comes to terrorism, individuals and groups simply contact ISPs and have content removed. The Internet Haganah, which calls for the removal of sites which allegedly support terrorism, had counted 600 successful takedowns by 2005. These include websites, groups hosted by Yahoo! and storefronts at Cafe Press. In 2005, the Toronto-based Friends of Simon Wiesenthal Center had several sites removed by their ISPs, one of which only contained a flag that carried the inscription, ‘There is no other God but Allah’. There was no hateful text or material advocating suicide bombing. The issue, as noted in the press release, was that the flag appeared to be the same one used by Hizb-ut-Tahrir, a group that, at the time, was not on the US State Department’s or Canada’s list of terrorist organisations.

While content removal remains largely undocumented, it is possible to interrogate the technical infrastructure through which countries block access. There is a variety of methods through which content on the Internet can be blocked that falls into three general categories: domain name server (DNS) tampering, Internet protocol (IP) address blocking, uniform resource locator (URL) filtering and keyword filtering.

DNS is the system that translates a domain name into a numerical IP address. By tampering with their DNS server, ISPs can force domain names to resolve to invalid or ‘spoofed’ IP addresses. The South Korean ISP, Kornet, resolves censored domains to an IP address which displays a police block page, indicating to the user that illegal content is being accessed. One of India’s leading ISPs, Videsh Sanchar Nigam Ltd, uses DNS tampering to block websites, forcing domains to resolve to the invalid address 1.2.3.4 India focuses its filtering on Hindu extremists and some American right-wing sites, as well as sites advocating a Dalit homeland. DNS tampering is easy to circumvent, as a user can simply configure their computer to use an alternate DNS server, but it is often used by ISPs to avoid problems with over-blocking.

Countries new to filtering will generally start with blocking by IP address, before moving on to more expensive URL filtering solutions. Most ISPs do not have the capacity to filter by URL and the ones that do would need to purchase a significant amount of equipment to implement URL filtering without a significant drop in performance. ISPs must often respond quickly and effectively to blocking orders from the government or national security and intelligence services. So they block material in the cheapest way, using technology already integrated into their normal network environment. Blocking by IP is effective (the target site is blocked) and no new equipment needs to be purchased. It can be implemented in an instant, as all the required technology and expertise is readily available. Many ISPs already block IP addresses to combat spam and viruses.

But blocking by IP address comes with a significant cost: over-blocking. Many unrelated websites may be hosted on a single IP address, so, when blocked, all other content hosted on the server will also be inaccessible. Pakistan is an interesting case, because it is one of the few countries in which the blocking lists have become public. Internet traffic routes through a gateway operated by the Pakistan Telecommunications Company Limited. Officially, Pakistan only blocks 17 sites, although the list contains dead sites and typographical errors. The OpenNet Initiative tested 11 of these designated sites. It found that, in total, nearly 3.5 million are actually blocked. This total does not, however, include the hundreds of thousands of individual blogs hosted on Google’s blogspot service. Pakistan has blocked access to the IP addresses of key hosting providers including GoDaddy and Yahoo! In the past, Pakistan has also blocked IP addresses associated with the mirroring company Akamai, causing hundreds of thousands of sites to become inaccessible.

This is the same technique that the Canadian ISP Telus used to block access to a union-affiliated site during a labour dispute. In the process, it blocked access to over 700 unrelated sites. This generated a considerable amount of criticism and clearly demonstrated the unintended consequences of filtering technologies.

Over-blocking tends to create a significant backlash, especially from non-activist Internet users. While people will often tolerate the blocking of extremist or offensive sites, when their own regular browsing and blogging is interrupted they quickly become aware of censorship’s impact and campaign against it. An excellent example has been the ‘Don’t Block the Blog’ campaign which was started after Pakistan blocked access to Blogspot; pkblogs.com now offers an alternate means of accessing Blogspot, bypassing Pakistan’s filtering. However, in response, the authorities will often seek to implement filtering techniques that better target the specific sites they want to block.

As the complexities of implementing an effective filtering system are recognised, countries are beginning to move towards the use of commercial filtering technology. In addition to the issue of over-blocking, filtering systems suffer from another inherent problem: under-blocking. Alongside the maintenance of blocking lists-which can be considerable for categories such as pornography-other forms of content need to be blocked in order to have a reasonably effective filtering system. This primarily involves finding and blocking sites that enable users to get around the filtering. Commercial technologies have enabled the expansion of Internet censorship, providing a fine-grain control over the filtering and monitoring process. They are equipped with easy-to-use graphical interfaces for management of the filtering system, as well as pre-configured blocking categories which include ‘anonymisers’-sites that allow one to bypass censorship.

There are a growing number of countries that use commercial filtering technology. However it is often difficult to determine the exact technology being used. To date, the OpenNet Initiative has identified the use of SmartFilter, produced by the US company Secure Computing, in Saudi Arabia, Tunisia, Oman, Sudan, United Arab Emirates, and possibly in Iran, while Websense and Fortinet are being used in Yemen and Burma respectively.

Commercial filtering technologies can be configured to block very specific content as well. In Saudi Arabia, for example, the websites of the Arab Human Rights Information Network and Humum are mostly accessible. Only specific pages about Saudi Arabia are blocked. They can also be used to avoid network degradation associated with other methods of filtering. Saudi Arabia claims that its system actually improves performance.

But commercial filtering technologies introduce additional concerns. The way in which these companies categorise websites affects access to the Internet more widely. SmartFilter, for example, is configured to block predefined categories of content: anonymisers, nudity, pornography, and sexual materials. Recently, the video-sharing website dailymotion.com was blocked in Tunisia. SmartFilter had temporarily categorised the site as pornography, and, since Tunisia blocks the pornography category, the website was blocked. Several days later, SmartFilter removed dailymotion.com from the pornography category and it became accessible.

In effect, governments are ceding the decision on what precisely to filter to unaccountable commercial entities. Due to the categorisation choices made by these companies, content may become inaccessible to entire populations, even if the government never intended to block the content. This situation is exacerbated by the intellectual property protections afforded to the companies. The block lists used by commercial filtering software are secret; decrypting and analysing them is considered to be illegal.

The chilling effect of legislation, such as the United States’ Digital Millennium Copyright Act (DMCA), has resulted in researchers stopping work on the impact of commercial filtering software. This is especially relevant because the software is increasingly turning up in undemocratic countries and is being used to filter all sorts of content-including political speech.

The work of two high-profile researchers was cut short in this field due to mounting legal risks. Ben Edelman sought to obtain a court judgment in order to protect himself from liability for decrypting the blocking lists of commercial filtering technologies, but his case was dismissed. Seth Finkelstein was forced to abandon work decrypting the blocking lists of filtering software products because of the associated legal risks.

Despite the obstacles, there are growing efforts to resist and challenge the spread of Internet censorship. These range from research projects designed to document and expose current censorship practices, to legal challenges to the development and use of technologies. Combined, these efforts seek to challenge the norms surrounding the practice of filtering, change the policies of governments and ISPs and empower users to protect their privacy and exercise the right of free expression online.

There are numerous human rights organisations investigating and highlighting egregious cases of Internet censorship, including Amnesty International, Reporters Without Borders and Human Rights Watch. These groups collect and analyse reports of blocked content, as well as create campaigns to highlight egregious cases of censorship and make that information available to a wide audience. They also seek to influence public policy and engage in lobbying and advocacy, targeting governments and corporations. Amnesty International started the irrepressible.info campaign that seeks to highlight Internet censorship by allowing website owners to display fragments of text taken from censored sites around the world. More than 70,000 people have signed the pledge calling for an end to ‘unwarranted restriction of freedom of expression on the Internet’. The signatures from this pledge were delivered at the 2006 Internet Governance Forum before an audience of governments and companies involved in censoring the Internet.

Reporters Without Borders maintains a list of imprisoned cyberdissidents and has also created the Handbook for Bloggers and Cyber-dissidents which provides information on how to secure one’s communications and bypass Internet censorship. Human Rights Watch has released detailed reports that not only document the technical aspects of filtering, but also the cases of individuals who have been directly affected by state censorship. The reports contain detailed recommendations for governments, corporations and activists to promote policies that enhance freedom of expression online.

In addition to major international organisations, there are coalitions such as the Global Voices Advocacy project and the Society Against Internet Censorship in Pakistan that seek to build alliances among bloggers and free expression advocates worldwide. There are also numerous grass-roots campaigns to free imprisoned bloggers around the world. The groups not only raise awareness about violations of freedom of expression, but also provide information on how to bypass Internet censorship and on strategies to maintain anonymity online.

While advocacy is an extremely important component in challenging censorship, there also exists the need to technically uncover exactly the methods and targets of state censorship. Research projects have been pivotal in establishing a body of credible evidence, exposing practices that are most often secretive and forcing governments and corporations to account for their censorship practices. Faced with accurate, empirical evidence, it becomes increasingly difficult for states to continue denying the fact that they are censoring the Internet.

The chillingeffects.org project, a collaboration between leading law schools and universities across the US, tracks notice and takedown requests. The majority of complaints relate to copyright and trademark infringement, but increasingly also cover libel and defamation. The project has tracked over 2,000 such notices. It also provides ‘weather reports’, which are a great resource for investigating the use of the law to remove content.

The OpenNet Initiative (ONI) has developed a set of tests that interrogate the Internet to identify filtered content. To date, ONI has tested in over 40 countries worldwide and has uncovered the techniques employed by states, usually at the ISP level, to filter the Internet. Moreover, ONI has begun to develop methods to monitor Internet access during key time periods, such as elections, in order to collect evidence of the temporary tampering with Internet access and in some cases denial of service to opposition websites. ONI has also identified technologies created by American companies, which are used to censor political speech in repressive countries. This work has informed a US Congressional committee that brought representatives from leading companies to explain their actions. ONI work has also been widely cited and used by human rights and press freedom groups around the world.

But while ONI has done excellent work in interrogating systems of Internet filtering, surveillance has proven to be much more elusive: it can be conducted in a passive manner and is thus extremely difficult, if not impossible, to document technically. Therefore, the majority of the work done in uncovering systems of surveillance has been through leaks, freedom of information requests and legal process.

The United States maintains the most sophisticated surveillance programme in the world. The American Civil Liberties Union (ACLU) created the ‘Surveillance Society Clock’, modelled after the doomsday clock, to symbolise just how much of a threat the current levels of surveillance in the US are to a free society. The clock is currently at six minutes to midnight.

Surveillance practices in the US are being challenged in the courts. The Electronic Frontier Foundation (EFF) and the Electronic Privacy Information Center (EPIC) have been extremely active in bringing legal challenges to uncover the vast surveillance programme. The EFF filed a lawsuit on behalf of AT&T customers to challenge the company’s participation in the National Security Agency’s (NSA) illegal domestic surveillance. The challenge was made after it was revealed that the NSA had been data-mining Internet and telephone logs from various telecommunications companies in the US without the proper legal authority. In response, the Bush administration is seeking to shield participating companies behind vaguely worded ‘state secrets’ protection. The Department of Homeland Security (DHS) and the Pentagon also maintain surveillance programmes. As a result of investigative reporting and the threat of legal challenges, two of these programmes have been suspended. The DHS suspended ADVISE (Analysis, Dissemination, Visualisation, Insight and Semantic Enhancement) after it was found to violate privacy laws. The Pentagon suspended its TALON database-which monitored peace activists amongst others-and the infamous Total Information Awareness project after similar concerns were mounted.

Legal challenges against Internet censorship are also being mounted worldwide. In Iran, the conservative website Baztab was filtered after several articles critical of President Ahmadinejad were published, but access to the site was restored following a successful legal challenge. The unblocking of one website-run by well-connected people-is a small victory, but it could be very significant. If the procedures for blocking content become transparent, if there is an appeals process and some level of accountability, it then becomes increasingly difficult for governments to justify censorship. Human rights groups have long called for a legally transparent process through which censorship can be challenged.

China has also been the site of a legal challenge-once largely thought to be impossible. A Chinese blogger known as Yetaai [see pp161-164] brought a case against China Telecom for blocking his website. It is seen as a landmark case because it may force the company or the government to admit that Internet censorship actually takes place. Although many believe that Yetaai will not be successful, his case has inspired others to use the legal system to challenge Internet censorship in China. Another blogger, Liu Xiaoyuan, has attempted to sue the Chinese company Sohu for censoring several posts on his blog, while a website, www.bullog.cn, is calling for public hearings to protect it from being shut down.

In another case that is emblematic of the global resistance to censorship, the family of Wang Xiaoning, an activist who was arrested and tortured in China, is suing Yahoo! in an American court because Yahoo! provided information to the Chinese government that was used in the prosecution. Yahoo! has filed a motion to dismiss the case.

This is not the first case in which Yahoo! has provided evidence to the Chinese government resulting in the conviction of dissidents. Chinese journalist Shi Tao was sentenced to ten years in prison in China, after distributing the Chinese government’s instructions to domestic journalists on how to cover the anniversary of the Tiananmen Square massacre. Shi Tao sent the information to a foreign-hosted dissident website from his Yahoo! email account. The Chinese government asked Yahoo! to provide information on the account details and this information was used in the case against Shi Tao.

The case illustrates that while many people assume that there is anonymity online, users have to protect themselves to keep their identity hidden. Technologies that make it possible to circumvent censorship and enhance the individual’s right to communicate and access information are also an important means for challenging censorship and surveillance. Filtering and monitoring communications online make it possible for hostile actors to find identifying information that may be used to arrest and imprison political dissidents.

In order to combat these growing threats, technologies are being developed to evade censorship and protect privacy. These same technologies are used by dissidents in politically repressive countries as well as activists in democratic countries. Peacefire, for example, is an organisation that develops and provides technology to evade censorship. It was formed to advocate on behalf of children who were being subjected to filtering in schools and libraries throughout the US. Peacefire now also focuses on providing these same censorship circumvention methods to users in China and Iran.

The technology allows a user in a censored location to connect to an unblocked, intermediary computer, in an uncensored location, to access content through the computer’s Internet connection. The user in the censored country does not directly access a blocked website, but asks the intermediary computer to do so. The intermediary computer retrieves the requested website and displays it back to the user.

While there are a variety of technologies available that can be used to circumvent censorship, there is a fundamental challenge: how to disclose the location of the uncensored intermediary to users who want to bypass censorship, while keeping it secret from agents who seek to find and censor these intermediaries. There are two main approaches to this problem: public and private. The public approach is to create numerous intermediary locations, through which users can bypass censorship and simply reveal more, through email lists, instant messaging and so on, as each becomes blocked. Censors who are slow to act will find more and more people using these circumvention systems. However, since many countries now use commercial filtering applications, the list of ‘proxy and anonymiser’ sites that these companies maintain are updated frequently, resulting in a situation where the lifetime of a new circumvention intermediary can last between one day and one week before being blocked.

Private circumvention solutions focus on distributing the location of the intermediary computer to people who know and trust one another. By leveraging these relationships of trust, a circumvention provider can slowly develop a network and provide stable circumvention services to a few-with a greatly reduced risk of being blocked by censors. Psiphon is a personal circumvention system that was designed and developed by the Citizen Lab at the University of Toronto. It allows users in uncensored locations to turn their own home computer into a circumvention server and allow their friends and family members in censored locations to surf freely. One of the goals of the project was to make the software extremely simple, so that those with limited technical abilities could make use of the technology.

There is an important distinction to be made between circumvention and anonymity technologies. Circumvention technologies focus, with varying degrees of security, on allowing users to bypass censorship, while anonymity technologies focus on protecting the users’ identity from outside observers, such as government surveillance, as well as from the anonymity system itself. Circumvention systems that use encryption can protect users in some surveillance scenarios, but are not anonymous because owners of the circumvention system can see everything that the user does. They also cannot protect users from traffic analysis attacks in the same way that anonymity systems can. Anonymity systems protect privacy by shielding the identity of the requesting user from the content provider. In addition, they employ routing techniques to ensure that the user’s identity is shielded from the anonymous communications system itself. In addition to providing anonymity, these technologies are also used in many countries to bypass Internet censorship. Anonymity systems are increasingly being recommended by privacy advocates. The Privacy Commissioner of Canada, for example, recommends that Internet users protect themselves online by using anonymity technologies, as well as anonymous remailers.

The most widely known anonymity system is Tor (see p143). It is promoted by the Electronic Frontier Foundation as software to protect privacy and civil liberties online and is used by bloggers who want anonymity, as well as by government embassies around the world. Tor works by routing a user’s request through at least three Tor servers. As the request hops from one Tor server to another, a layer of encryption is removed, so no individual server knows both the original source and destination of the request. The last server in the chain of hops, known as a circuit, actually connects to the requested content and then sends that information back through the circuit to the user. However, anonymity technologies are currently not difficult to block. Tor’s developers are working on building in blocking resistance to the anonymity system.

The Internet is a tool, like any other, that can be both used and abused. We know that governments around the world, much like companies, schools, libraries, and parents, restrict access to Internet content they do not want their citizens, employees, students, patrons and children to see. However, there is a failure to recognise Internet censorship and surveillance as a growing global concern. There is a tendency instead to criticise the most infamous offenders-notably China and Iran-and to overlook repressive practices elsewhere. Focusing on the global character of both the practice of Internet censorship and surveillance, as well as the resistance to it, provides for both a better understanding of this important trend as well as for the possibility of creating global alliances to combat its spread.

One software program called Psiphon, which was developed by researchers at the University of Toronto’s Citizen Lab, allows any person with a computer to serve as a proxy for someone living behind a firewall. Since it was launched a year ago, more than 100,000 people have turned their personal computers into proxies.

The most sophisticated proxy technology may be Tor, developed jointly by the U.S. Naval Research Laboratory and the Electronic Frontier Foundation, an Internet freedom advocacy organization. Tor is a downloadable software that routes an Internet surfing session through three proxy servers randomly chosen from a network of more than 1,000 servers run by volunteers worldwide. “Tor is state of the art,” says John Mitchell, an expert on Internet security at Stanford University. For citizens of repressive regimes, it may be the best hope or evading the cat’s paw.

This partial picture ignores the global use of these technologies. More and more countries are censoring the Internet — not just China and Iran.

Here’s an interesting anecdote. When psiphon was released the CBC, Canada’s national public broadcaster, covered it but the reporter working on the story had to phone me at the Citizen Lab because she could not access the psiphon website from CBC because it was blocked by their filtering software, aka censorware. This is not the first time I’ve heard this. Reporters at CBC need to use tools like psiphon to do their jobs!

The other missing piece is surveillance. The U.S., which has the most sophisticated electronic surveillance program in the world, has been caught illegally spying on citizens. Anti-Censorship/privacy enhancing technologies are used all over the world. Even the Privacy Commissioner of Canada recommends that Canadians use anonymous communications technologies. These are tools developed for and used by people all over the world. To pitch them as something that’s only used in repressive countries is misleading and inaccurate.

The guide walks users through the process of assessing their needs and and capabilities and lists clusters of circumvention technology options for users to choose from.

Recent coverage of the protests in Myanmar/Burma have generally been falling into the latter camp. Noting that, according to ONI, Myanmar/Burma has one of the most restrictive Internet filtering systems in place this article wonders why information about the protests is getting out. It claims that “the cyber-reality in Myanmar is actually much less restricted than ONI’s research indicated” because circumvention technologies are available to citizens.

Filtering technologies seek to keep citizens inside Myanmar/Burma from have access to sites hosted outside — it does not say much about keeping information from moving in the opposite direction. Why? Because sites are filtered when they are contextually important, become well known, and/or can reach a large audience. For information to flow from a few to these sites if far harder to control than the information from these few sites to the many.

Similarly, while there are censorship circumvention technologies readily available these are used by the few not the many for a variety of reasons including fear of being caught, lack of technical ability, or just now knowing (or caring) about them.

Internet censorship regimes, such as Myanmar/Burma’s, are effective not because they can filter out all the content they want but because their filtering systems are backed up by other forms of repression that force users into a condition of self-censorship where they will not seek out banned content (the filter is just a reminder) let alone seek to violate their countries laws and put themselves at risk by using circumvention technologies.

So the reality is actually somewhere in between. While the majority are kept in line by the filtering matrix, there is a still resistance. Determined Internet users can use a variety of methods to bypass censorship while others speak out publicly and risk repression. All of this slowly widens the scope of accepted speech within these confined spaces — not cataclysmic event.

ToR isn’t the problem, just use it for what it’s made for.

This reminds me of the “trick” a lot of people use in which they set up an email account but don’t actually send email but rather just store email in the drafts folder thinking that this protects them from government surveillance. Unless the full session is encrypted, and many using this technique are using web mail account which only encrypt the login not the rest of the traffic, it can still be snooped even though you are not “sending” the email.

• Dissidents find ingenious ways to hide digital traces

TOR can be used for both anonymity and censorship circumvention, but while “anonymous” proxies can be used for censorship circumvention they not really anonymous. A “proxy” may sheild your identity from the website you are visiting but it does not hide you or anything you are doing from the owner of the proxy. And if the proxy is not encrypted — most of the “open” proxies are not — then anyone monitoring Internet traffic can also see everything you do through the proxy. TOR, on the other hand, encrypts your traffic and hides what you are doing from the TOR network itself, it is hardly comparable to “open” proxies. I have not looked closely at GPass, but it appears to be an encrypted Socks proxy, and if so, is not anonymous — all traffic through it can be viewed by the owners of GPass. (And you don’t have to use Swedish Google, Google just redirects you to the localized version, you can always click the google.com link and use google.com).

• Repressive governments widen stifling techniques

It is not only “repressive” governments that are increasing their level of filtering and employing new techniques (new techniques for the country, not for filtering in general), countries such as India and Thailand are filtering as well. There is a tendency to analyze all regulations and restriction in particular countries, such as China and Iran, out of context. For example, there is a tendency to think of China’s Internte cafe’s as places teeming with cyberdissdents and therefore when China closed many and instituted restrictions after a deadly fire in an unlicensed cafe many interpretted it as a crackdown on free expression. I think that the Iranian bandwidth limitation story may prove to go this way as well — it’s more likely to do with porn than with politics. But, hey, I could be wrong.

Human rights groups and NGO’s worldwide have long protested that they are often the victims of state surveillance, computer breakins and denial of service attacks. ONI has documented an attack on Kyrgyz opposition newspaper websites during that countries elections in 2005 and there have been reports of such Denial of Service attacks during elections in Belarus as well. What is new is not the technique but the correlation between the target — important opposition website — and the time period — during an election. Denial of Service disrupts access to a website for everyone — as opposed to filtering which would only block it from the affected location. It also provides deniability on the part of the government. In the Kyrgyz case, the attacks appear to have been conducted by a “botnet for hire” leaving the conection to the government circumstantial. This is a trend we will probably see more of especially in countries that don’t have a national filtering system (or officially filter very little content).

• Web censorship spreading globally

A good article about the forthcoming ONI study, however, some instances listed as “new censorship techniques” are not really new at all. They may be new to certain countries, but they are standard filtering techniques. And there is not yet evidence that Zimbabwe is censoring the Internet, let alone using the same techniques as China. I have heard reports about this, but even if they are true, it has not been implemented.

The aim of the ONI is to document empirically patterns of Internet content filtering and surveillance worldwide behind national firewalls over an extended period of time. Its reports have documented the scope, scale and sophistication of numerous filtering regimes worldwide, and have helped verify the use of commercial filtering technologies that are used to underpin these regimes. The ONI’s flash map of global filtering shows the results of these investigations.

But, as Bennett Haselton points out, there are weaknesses in various circumvention methods. It is important to remember that in some countries the decision to circumvent censorship is extremely important, the consequences may be severe. The context — regulations as well as level of actual enforcement — for each country will vary. Users need to be aware of the potential consequences and then make their decision.

In terms of actual use, the major issues with circumvention systems are ease of use and, as Paul Baranowski points out, the discovery mechanism:

The challenge is to prevent attackers from discovering enough nodes to disrupt the network while still allowing users to discover enough nodes to remain connected to the network.

There have been, primarily, two approaches adopted: public systems and private systems. With public systems — e.g. proxy addresses distributed via email or software that users can install and connect to a circumvention or anonymity system — one must assume that the censors also discover and subsequently block these systems. these systems exploit windows of opportunity or the period of time that it actually takes the censors to block new public circumvention locations. The difference with private systems — which can be the same technical solution as public systems — is that the location is only sent to a few, ideally trusted, people. In that way the censors cannot easily find and block the location of the circumvention system. However, this requires people to have contacts outside of their own country.

Our system leverages social networks as the discovery mechanism. The provider and the user(s) have a trust relationship and the circumvention location is known only to these trusted people. The limitation is that a user in a censored country must know someone in an uncensored country. I’ll be posting more shortly but, this is the key concept. there is no censtralized system. Each network of provider/users chooses how to grow the network. It can be small and extremely private or large and relatively semi-private. It depends on the specific context in which the users (in censored countries) live.

More to come…

The filtering takes place in at least three ways:

• de-listed domains: specific websites are removed entirely from search results; it is as if the website never existed.
• de-listed urls: specific urls are removed from search results if they contain a de-listed domain.
• restricted keywords: specific keywords are restricted to searches of web pages hosted in China only.

The New York Times reports that the Chinese government did not give Google a list of sites to block. Rather, Google set-up a computer in China and tested to see what content was accessible and content found to be inaccessible was deemed to be sensitive and added to Google’s blocklist.

For example, the website for Human Rights Watch (hrw.org), which is blocked in China, has also been de-listed from Google.cn. A normal web request to hrw.org from within China triggers an error and the content of the site never loads in a users browser. A search in Google using the modifier “site:” for content on hrw.org (site:hrw.org) on Google.cn yields no results. In China, it is as if hrw.org does not exist.

Is there a way to circumvent Google’s censorship in China?

Google has an advertisement program, Google Adsense/Adwords, that allows one to purchase certain keywords that will display an ad on Google when users search for those words. I created an account with Google Ads and selected that my ad be shown in Chinese to users in China. I noticed that a warning appeared indicating that there may be restrictions on advertising in China.

Google describes some specific categories of content that require licensing (local pdf). This list does not include content that may be sensitive for political reasons.

Due to advertising regulations and laws of the People’s Republic of China, Google AdWords requires advertisers to submit business licenses and approval certificates for the following product categories: Agricultural Chemicals Books/Periodicals Cosmetics Food/Foodstuffs Health Supplements Medical Appliances Medical Services Patents Real Estate Veterinary Medicine

I created my ad (which does not appear to fall under these categories) for hrw.org, which is censored by google.cn, and it was held in a queue waiting to be viewed and labeled “Family Safe”. Only “Family Safe” ads are allowed to be shown by Google in China. Eventually my ad was approved as “Family Safe” and was labeled as currently being shown.

However, my ad was initially not shown on Google.cn.

Google indicates that there is an ad for the search terms I selected, but it is not shown. I emailed Google for an explanation of why my ad was not being shown and was informed that there may be a technical error.

My ad was being shown on the uncensored Chinese language Google, but not the censored Google.cn. Google checks what ads to deliver by location (determined by IP address) and the language setting of your browser. Despite both of these showing that my language was Chinese and my location was in China the ad did not properly appear.

Eventually, my ad began to be shown on Google.cn. While my ad does not appear every time the keywords are searched, it does periodically appear. (See possible explanation below).

Although there are no search results available for hrw.org, my ad for a censored website did appear on some occasions. (See below for a possible explanation.)

This is a neat way to circumvent Google’s censorship. It may be possible to extend this even further. Mirror sites and alternative URLs for censored web sites can be displayed through the use of Google Ads.

For the techies out there…

www.google.cn resolves to several IP addresses:

$ host www.google.cn
www.google.cn is an alias for cn.l.google.com.
cn.l.google.com has address 64.233.189.161
cn.l.google.com has address 64.233.189.162
cn.l.google.com has address 64.233.189.160
cn.l.google.com has address 66.249.89.162
cn.l.google.com has address 66.249.89.161
cn.l.google.com has address 66.249.89.160

When connecting directly to these IP addresses and manually inserting the Host header (Host: www.google.cn) the normal google.cn appears (with filtered results), but the ad is missing.

When connecting directly to alternate Google IP addresses, such as 216.239.57.99 and 64.233.171.99 and manually inserting the Host header (Host: www.google.cn) the normal google.cn appears (with filtered results), the ad does appear.

It appears that some specific IP addresses assigned to serve www.google.cn do not consistently show the ad, while other Google IP addresses do consistently show the ad.

I am still waiting for an explanation from Google.

Mr. Chairman and Members of the Caucus:

On behalf of the Citizen Lab, I would like to thank the Congressional Human Rights Caucus for inviting me to speak on the issue of Human Rights and the Internet. As Director of Technical Research for the Citizen Lab I have worked extensively over recent years on the OpenNet Initiative, a collaboration between the Munk Centre for International Studies at the University of Toronto, the Berkman Center for Internet & Society at Harvard Law School, and the Cambridge Security Programme at Cambridge University focused on the study of Internet filtering and surveillance worldwide.

Although Internet censorship in China has received the most attention, and is the focus of the hearing today, Internet censorship is a growing trend worldwide. The OpenNet Initiative has released eight major country studies on Internet filtering and has investigated forms of Internet filtering in nearly thirty countries spanning different cultures, religions, languages, ideologies, economic systems and governments both authoritarian and democratic.

Governments around the world, much like companies, schools, libraries, and parents, are beginning to restrict access to Internet content they don’t want their citizens, employees, students, patrons and children to have access to. There are many ways, both technical and non-technical for governments to disrupt or monitor online communications. In fact, all governments do it to a certain degree with some focusing on blocking content, such as web sites, while others focus on monitoring communications, such as email. Some governments, such as the government of China, do both.

China, much like other countries, is seeking to assert information sovereignty in cyberspace through the implementation of national filtering and monitoring systems that block access to Internet content deemed undesirable and limit citizens’ ability to organize and communicate online. This Internet filtering is being implemented in a manner that lacks openness, transparency, and accountability. National filtering is generally implemented at Internet Service Providers (ISP) or at centralized gateways where connections are made to the international Internet. When connections are made to prohibited content the filtering system blocks access to the requested content and is often used in conjunction with a logging system that records the violation. In some cases countries use routers to block access to specific content while others use specific technology designed for content filtering and caching.

Although the emphasis is often placed on the technical side, national Internet filtering is best described as a matrix of control in which technological and non-technological measures intersect at different levels of access to enforce strict information control policies. While it is true that Internet censorship is not, on a technical level, always 100% effective, countries like China can and do maintain an effective censorship policy combining filtering and surveillance technology with fear, intimidation and imprisonment.

In China, the government has established a complex web of regulations for both Internet Service Providers (ISP) and Internet Content Providers (ICP). These regulations manage the delivery of Internet access as well as content within China and define the enforcement policies and mechanisms through which compliance with the regulations is achieved. Although the Ministry of Information Industry (MII) is responsible for the Internet infrastructure, the Ministry of Public Security and the State Secrets Bureau are also involved in the filtering process. While there are explicit regulations that forbid the use of the Internet to incite the “overthrow of the government or socialist system” or “promote feudal superstitions,” it is unclear which specific laws or regulations mandate the use of backbone Internet filtering. Nor is it clear how specific content is chosen to be blocked.

China deploys Internet filtering technology at the Internet backbone level, near international gateway points. Requests for blocked content are routed normally through regional networks but are blocked before the request leaves China’s backbone network and enters the international Internet. China configures these gateway routers, which are believed to be manufactured by Cisco, to block access to specific Internet Protocol (IP) addresses, domain names, and keywords that appear in Uniform Resource Locator (URL) paths. When this filtering mechanism is triggered the connection between the user in China and the external host is disrupted. This affects all manner of web traffic including browsing websites and submitting queries to search engines.

The content that China targets for filtering, which we’ve been able to empirically document through technical means, contains content related to Taiwanese and Tibetan independence, the Falun Gong movement, the Tiananmen Square crackdown, human rights organizations and foreign media, mostly U.S. Government funded news sites such as Voice of America. Although China has been shutting down domestically hosted pornographic sites, pornographic sites hosted abroad have not been systematically targeted.

This brief list is less than comprehensive as it represents the most common or obvious content areas. No country, or company for that matter, is completely open about what is specifically filtered. The filtering regime in China operates with a lack of transparency and openness. There is no public list of banned sites or keywords and no mechanism for citizens to petition to have a site unblocked. One of the measures of transparency is the behavior users observe when attempting to access filtered content. In some countries users are presented with a “block page” which informs the users that their request has been blocked. However, in China, users simply see a generic “error page” that does not indicate that the request has been blocked and simply leaves the user to wonder if the content has been censored or if there has been a common network error.

Filtering and monitoring of online communications presents a serious threat to personal privacy and public discourse online. The right to communicate freely is clearly articulated in the Universal Declaration of Human Rights and is currently under severe threat in China.

In addition to the backbone filtering deployed in China, Internet filtering is now occurring at multiple levels of access and filtering is increasingly being built-in to applications and web services themselves. Domestic Chinese search engines, such as Baidu and Yisou, implement their own filtering to exclude search results from websites that provide information the government considers “sensitive”. Domestic blog providers technically prohibit the posting of blog entries that contain “sensitive” key words and popular Chinese web portals have been known to remove posts from their web forums that contain “sensitive” information. This “self-regulation” is a key component of China’s overall filtering regime.

Now foreign companies eager to do business in China are implementing similar filtering systems. Microsoft’s MSN spaces has implemented filtering on their blogging service restrict users from creating posts with the words “democracy” and “freedom” in the subject line. Yahoo! and Google now filter parts of their search engines that are marketed for users in China. Google.cn filters news.bbc.co.uk, hrw.org and restricts results for sensitive terms to web pages hosted in China.

This is part of a larger phenomenon in which countries such as Burma, Saudi Arabia, United Arab Emirates (UAE), Tunisia, Yemen, Sudan and until recently Iran, all use commercial filtering products developed by U.S. corporations. The manufacturers of these filtering products are effectively determining what content citizens in these countries can view and the block lists they sell are secret and not open to public scrutiny.

What we are witnessing is, in effect, a market failure that puts profit and market share above ethics and human rights. Companies that self-censor their services are doing so in a way that mirrors that lack of openness, transparency and accountability that is emblematic of China’s own filtering regime. These companies, like China, do not disclose what websites and keywords are being filtered. Nor have they disclosed how the list was created or came into their possession. None of these companies has so far indicated what specific law or order is being complied with.

The acquiescence to China’s censorship demands sends the message to the world that political censorship is normal and acceptable. This acts to normalize the Internet as an environment that is hostile to civil liberties, freedom of speech, and free expression. In many countries the Internet is the last frontier as all other forms of media are tightly controlled.

Even within confined, controlled spaces democratic practices can make headway. As the boundaries of information control are challenged and new locations of public debate expanded democratic practices are enhanced. While previous efforts have focused on sending information through to people in China new technologies are enabling Chinese users, who are willing to take the risk, to circumvent Internet censorship. Internet filtering alone, especially when restricted to Web–based filtering, cannot completely control a person determined to access blocked content. Filtering systems can be circumvented through the use of censorship circumvention systems and anonymous communications systems.

Furthermore, new technologies and services, such as blogging, are now enabling a two-way information flow which gives those outside of China the opportunity to listen as Chinese users express themselves online. Despite the restrictions on external content, Chinese users have begun to use the Internet to communicate and coordinate at the local level within China’s restrictive information environment.

The outcome of these emerging trends is uncertain. I remain cautiously optimistic because despite these repressive controls Chinese Internet users have proven to be resourceful and resilient. But China is certainly seeking to maintain its strict information control and companies that enable and conform to Chinese censorship policies are further confining the spaces in which China’s citizens can express themselves online.

Thank you.

Nart Villeneuve
Director of Technical Research, Citizen Lab
Munk Centre for International Studies
University of Toronto

In the second half of the presentation we focused on censorship circumvention. I like to talk about circumvention from two perspectives: push & pull. The “push” strategy if from the perspective of content producers and I hoped to use the discussion to start developing a sort of “best practices” document for content producers who expect their content to be blocked.

The final part of the presentation focused on pull strategies, basically proxies/anonymizers etc… — technology that enables users to select filtered content to view. Most of the strategies from this perspective are detailed in “Choosing Circumvention“. We also demo’d psiphon :)

The slides from the presentation are available here:
http://www.nartv.org/ppt/uk-prz.ppt.