From The Economist
Cat and mouse: How China makes sure its internet abides by the rules
THE HISTORY OF the internet in China is one of give and take, of punch and counterpunch, where the authorities are often surprised by the force and speed of online interactions but determined to keep them under control. The result has been a costly and diverse industrial complex of monitoring and censorship. Central-government ministries have invested in two pillars of control: the Great Firewall, a Western name for a system of blocking foreign websites, starting in the late 1990s, which some believe has cost as much as $160m (the details are state secrets); and Golden Shield for domestic surveillance and filtering, begun in 1998 by the Ministry of Public Security and estimated to have cost more than $1.6 billion so far....
Surprisingly, the machinery of control is far from monolithic, and rife with inconsistencies (especially from province to province: one study found that more than half the microblog posts in Tibet were deleted, compared with barely a tenth in other provinces). It is also much less automatic than might be expected. Academic studies of Chinese censorship show that for all the software and hardware involved in detecting and filtering content, much of the deleting is done manually, blog post by blog post, tweet by tweet...
Some disgruntled or liberal-minded employees clearly view the system as flawed and are providing information about its shortcomings to overseas sites. China Digital Times, a blog run by a dissident exile, Xiao Qiang, from the University of California, Berkeley, regularly publishes transcriptions of propaganda directives under the heading “Ministry of Truth”....