China’s system of Internet censorship and surveillance, popularly known as the “Great Firewall,” is the most advanced in the world. In this 149-page report, Human Rights Watch documents how extensive corporate and private sector cooperation – including by some of the world’s major Internet companies – enables this system of censorship. Research was performed through interviews and extensive testing of search engines in China, and includes 18 screen shots to illustrate examples of censorship. The report vividly illustrates how various companies, including Yahoo!, Microsoft, Google, and Skype block terms they believe the Chinese government will want them to censor.