Internet Filtering in China in 2004 2005 

persecution were received at our sina.com.cn account from our first sending account, but not from our 

second account.  Overall, when we analyzed results for the two sets of messages combined, every message 

with material on sensitive topics in English was received at all our e mail accounts in China. 

We tested the same messages in Chinese by sending two sets of these ten messages, encoded in 

different character sets.  (There are multiple character encoding settings used to display Chinese 

characters.  We sent messages encoded both in GB 2312, the official character set of the People s Republic 

of China, and in UTF 8 Unicode.)  Our results varied depending on the encoding of the message. 

In our Unicode testing, we found that all the messages were received, except for six of ten 

messages sent to our account at sina.com.cn.  The six messages that we did not receive at our sina.com.cn 

account were those containing content on protests by Tiananmen mothers, media censorship, religious 

persecution, political dissidents, arrests and sentences, and petitions and protests.  (However, we did 

receive each of these messages at sina.com.cn when they were encoded in GB 2312.) 

In our GB 2312 testing, we saw much lower success rates at receiving messages.  We did not 

receive three of the messages   those concerning the Tiananmen mothers, media censorship, and 

surveillance   at three or more of our five accounts.  In addition, the message concerning religious 

persecution was not received at our citiz.net e mail account.   

Overall, our results do not suggest consistent e mail filtering in China.  None of our test messages 

containing sensitive content was blocked by all five e mail service providers in China, indicating that 

filtering of e mail traffic at the backbone level of the network either does not exist or is inconsistent.  

Instead, our results suggest that individual e mail service providers may filter messages at the mail server 

level in a non uniform fashion. 

G. Blog Filtering Testing 

Today, Chinese servers host an estimated 600,000 bloggers, who post content ranging from daily 

diaries to political commentary.

164

  Over the last year, China intensified efforts to control blogs' content.  

In March 2004, the state closed three popular, domestic blog providers,

165

 reportedly because a blogger 

posted a controversial letter regarding the Tiananmen Square incident and the SARS outbreak.

166

Subsequently, all three providers were allowed to re open, but implemented filtering mechanisms to 

control content posted to their blogs.  These systems search for sensitive keywords when users attempt to 

post material. 

In August 2004, Chinese hackers discovered a list of 987 sensitive keywords (in both Chinese and 

English) in a component of the popular QQ instant messaging.

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  The software filters messages with these 

164

 Estimates of the total number of blogs in China vary; we used the number provided by CNBlog.org, at 

http://www.cnblog.org/index.html.   

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 These providers are blogcn.com, blogbus.com, and blogdriver.com. 

166

 See Juliana Liu, China Shuts Down Two Internet  blog  Sites, Reuters, available at 

http://asia.news.yahoo.com/040318/3/1eig1.html (March 18, 2004); see also China Doctor Calls 1989  Mistake,  BBC 

News, at http://news.bbc.co.uk/2/hi/asia pacific/3542049.stm (March 8, 2004) (discussing the content of the letter 

criticizing China s response to the Tiananmen demonstrations). 

167

 See The Words You Never See in Chinese Cyberspace, China Digital News. 

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