Human Rights Watch has a 149pp report on how China keeps control of free thought on the net, including with co-operation from Microsoft, Skype, and search engines. Parliament's Foreign Affairs committee also denounced such collaboration as 'morally unacceptable', and HRW suggests ways of bringing pressure to bear. The report itself is also likely to be censored - read our mirror of it here.

http://www.hrw.org/english/docs/2006/08/09/china13940.htm