Google explains itself on China.
Google in China
Filtering our search results clearly compromises our mission. Failing to offer Google search at all to a fifth of the world’s population, however, does so far more severely. Whether our critics agree with our decision or not, due to the severe quality problems faced by users trying to access Google.com from within China, this is precisely the choice we believe we faced. By launching Google.cn and making a major ongoing investment in people and infrastructure within China, we intend to change that.