Or so claims Reporters without Borders, which can be prone at times to hype. I think it would be fairly simple for users in China to test out its claims.

Reporters Without Borders said it found Yahoo! to be the clear worst offender in censorship tests the organisation carried out on Chinese versions of Internet search engines Yahoo!, Google, MSN as well as their local competitor Baidu.

The testing threw up significant variations in the level of filtering. While yahoo.cn censors results as strictly as baidu.cn, search engines google.cn and the beta version of msn.cn let through more information from sources that are not authorized by the authorities.

While Microsoft has just said it does not operate censorship, Reporters Without Borders found that the Chinese version of its search engine displays similar results to those of google.cn, which admits to filtering its content. Searches using a “subversive” key word display on average 83% of pro-Beijing websites on google.cn, against 78% on msn.cn. By contrast, the same type of request on an uncensored search engine, like google.com, produces only 28% of pro-Beijing sources of information. However, Microsoft like Google appears not to filter content by blocking certain keywords but by refusing to include sites considered illegal by the authorities.

The press freedom organisation is particularly shocked by the scale of censorship on yahoo.cn. first because the search results on “subversiveâ€? key words are 97% pro-Beijing. It is therefore censoring more than its Chinese competitor Baidu. Above all, the organisation was able to show that requests using certain terms, such as 6-4 (4 June, date of the Tiananmen Square massacre), or “Tibet independence”, temporarily blocked the search tool. If you type in one of these terms on the search tool, first you receive an error message. If you then go back to make a new request, even with a neutral key word, yahoo.cn refuses to respond. It takes one hour before the service can be used again. This method is not used by any other foreign search tools; only Baidu uses the same technique.

Censoring more than China’s own search engine? Shutting down for an hour? It sounds like Yahoo is working overtime to please its masters in Beijing. As I’ve said in the past, I take RSF’s reports with a grain of salt, but some of these claims seem fairly simply to test if you’re in China (and if you don’t mind being shut out of Yahoo for an hour).