The campaign involves seven government agencies, including the State Council Information Office, the Ministry of Industry and Information Technology (MIIT), and the Ministry of Public Security (MPS), according to a (in Chinese) carried on the MPS Web site.

Internet access to pornographic content harms the morality and health of young people and is a violation of Chinese law, the statement said.

In a (in Chinese) posted on MIIT's Web site, Google topped the list of Web sites that the Chinese government wants to see reign in access to Internet pornography. Other sites targeted by the campaign include Baidu.com, the country's most popular search engine and Google rival, as well as Internet portals like Sina.com. Sohu.com, Netease.com and QQ.com.

While search engines like Google and Baidu don't publish their own content, they are responsible in China for the content that users can access. In practical terms, this means they are required to censor access to subjects like the Falun Gong spiritual sect or Tibetan independence, for example.

While access to politically sensitive topics remains restricted on some sites, racier content is widely available.