American researchers report that the Chinese government has successfully blocked about ten percent of the Internet from Chinese users. Most of the sites blocked are political and provide information that the government disagrees with or would rather not have available to the Chinese people. The government admits that there is screening, but that it is mainly to block pornography sites. However, the researchers found that the vast majority of porn sites could be reached by Chinese users. The government's attempt to control Internet access is the most ambitious ever attempted. For most Chinese users, the controls work. More expert Internet users can get around much of the screening, and the government has been unable to effectively monitor email and instant messaging. But 42 of the 100 most popular worldwide news sites were blocked. Most of China 45 million Internet users, in effect, cannot reach sites the government does not want them to see. This is having an effect on Chinese public opinion, as foreign reporters find that Chinese internet users are usually ignorant of news events widely covered on the Internet, but blocked in China.