A comparison of search engines Yahoo!, Google, MSN and Baidu in China revealed some surprising results, says the organization Reporters Without Borders. The group said Yahoo! was the worst offender in the censorship tests, filtering even more information than its local Chinese competitor, Baidu.

The study used Chinese language search terms, including "democracy," "human rights" and "Tibet independence." In Yahoo!'s case, typing in certain search terms returned an error message the first time, and shut down the service for an hour the second time, the group reported.