Until march, 2010 google the chinese government censor the internet and track what its citizens were searching.

The operations of U.S. Internet companies in China are attracting concern in Congress after years of complaints from free speech and human rights advocates about these firms aiding Beijing’s ability to censor content. Trade liberalization has sent China’s economy booming, making it an attractive—even essential—market for U.S. companies to enter. But China’s government has retained tight political controls. China is believed to have the world’s most sophisticated network for monitoring and limiting information online. Combined with Beijing’s controls on traditional media, this Internet surveillance program has limited domestic debate on issues such as China’s human rights record, Tibetan independence, or Taiwan.