Internet Filtering in China in 2004 2005 

1. E

XECUT IVE 

S

UMMARY

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China's Internet filtering regime is the most sophisticated effort of its kind in the world.  

Compared to similar efforts in other states, China's filtering regime is pervasive, sophisticated, and 

effective.  It comprises multiple levels of legal regulation and technical control.  It involves numerous state 

agencies and thousands of public and private personnel.  It censors content transmitted through multiple 

methods, including Web pages, Web logs, on line discussion forums, university bulletin board systems, 

and e mail messages.  Our testing found efforts to prevent access to a wide range of sensitive materials, 

from pornography to religious material to political dissent.  ONI sought to determine the degree to which 

China filters sites on topics that the Chinese government finds sensitive, and found that the state does so 

extensively.  Chinese citizens seeking access to Web sites containing content related to Taiwanese and 

Tibetan independence, Falun Gong, the Dalai Lama, the Tiananmen Square incident, opposition political 

parties, or a variety of anti Communist movements will frequently find themselves blocked.  Despite 

conventional wisdom, though, ONI found that most major American media sites, such as CNN, MSNBC, 

and ABC, are generally available in China (though the BBC remains blocked).  Moreover, most sites we 

tested in our global list's human rights and anonymizer categories are accessible as well.  While it is 

difficult to describe this widespread filtering with precision, our research documents a system that 

imposes strong controls on its citizens' ability to view and to publish Internet content.   

Unlike the filtering systems in many other countries, China's filtering regime appears to be 

carried out at various control points and also to be dynamic, changing along a variety of axes over time.  

This combination of factors leads to a great deal of supposition as to how and why China filters the 

Internet.  These complexities also make it very difficult to render a clear and accurate picture of Internet 

filtering in China at any given moment.  Filtering takes place primarily at the backbone level of China's 

network, though individual Internet service providers also implement their own blocking.  Our research 

confirmed claims that major Chinese search engines filter content by keyword and remove certain search 

results from their lists.  Similarly, major Chinese Web log ( blog ) service providers either prevent posts 

with certain keywords or edit the posts to remove them.  We found also that some keyword searches were 

blocked by China's gateway filtering and not the search engines themselves.  Cybercafes, which provide an 

important source of access to the Internet for many Chinese, are required by law to track Internet usage 

by customers and to keep correlated information on file for 60 days.  As a further indication of the 

complexity of China's filtering regime, we found several instances where particular URLs were blocked 

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 The OpenNet Initiative is a collaborative partnership between three leading academic institutions: the 

Citizen Lab

 at 

the Munk Centre for International Studies, University of Toronto, 

Berkman Center for Internet & Society

 at Harvard 

Law School, and the 

Advanced Network Research Group

 at the Cambridge Security Programme (Centre for 

International Studies) at the University of Cambridge.  As with all OpenNet Initiative work, these reports represent a 

large team effort. The work of principal investigators Jonathan L. Zittrain and John G. Palfrey, Jr. on this research 

report was made possible by a grant from the John D. and Catherine T. MacArthur Foundation's Research and 

Writing Grants Program of the Program on Global Security and Sustainability.  ONI thanks Che Dong, Alana 

Maurushat, Rebecca Vaughn, and a number of anonymous volunteers for contributing key research to this study. 

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