The Chinese version of Yahoo Inc.'s search engine was the worst offender in censorship tests that included rivals Google Inc., Microsoft Corp.'s MSN and local competitor Baidu, an international free press advocacy group said.
Yahoo.cn was also found to censor search results as strictly as Baidu.cn, while Google.cn and beta version of MSN.cn let through more information from sources not authorized by Chinese officials, Reporters Without Borders said.
The Paris-based group said in a statement that it was "particularly shocked" by the scale of censorship on Yahoo.cn. Search results on key words deemed "subversive" by Chinese authorities returned results that were 97 percent pro-Beijing, more than its Chinese rival Baidu.
Requesting information on certain terms, such as the date of the Tiananmen Square massacre or "Tibet independence," would cause the Yahoo.cn search tool to return an error message, the advocacy group said. As a result, the search engine would not respond to any query for about an hour. This method is not used by any other foreign search tools, but Baidu uses a similar technique.
Yahoo officials in the United States were not immediately available for comment.
The tests showed that Microsoft and Google were also filtering results. Searches for "subversive" keywords returned on average 83 percent pro-Beijing Websites on Google.cn, and 78 percent on MSN.cn. By contrast, the same searches on uncensored search engines like Google.com produced only 28 percent of pro-Beijing sources of information.
Microsoft and Google appeared not to filter content by blocking keywords, but by refusing to include sites considered illegal by the Chinese government, the group said.
While Microsoft and Google run their own Chinese search tools, Yahoo turned over its operations last year to Chinese marketplace Alibaba.com. Yahoo, however, paid $1 billion for a 40 percent stake in the company.
Following laws that restrict access to information has become a part of doing business for Internet companies in the communist nation. As a result, some of those companies have been forced to take actions viewed unfavourably in democratic nations.
Microsoft in January, for example, took down the blog of outspoken Chinese journalist Zhao Jing, in order to comply with China's rules. Yahoo last year gave information about journalist Shi Tao's personal email account to Beijing, which later jailed him for 10 years on charges of divulging state secrets.
Reporters Without Borders believes search engines operating in oppressive countries do not need to compromise their values.
"We are convinced that these companies can still access the Chinese market without betraying their ethical principles," the group said in a statement. "They must however adopt a firm and clear position in relation to the Chinese authorities."
Despite censorship, six out of 10 Chinese users believe the Internet will provide more opportunities for criticising the Beijing government and nearly half think that going online will help them learn more about politics, according to a survey last fall by the Chinese Academy of Social Sciences of Beijing and the Markle Foundation, a New York-based philanthropy that focuses on information technology.
The survey also found that many Chinese believe the Internet will increase political transparency. That premise was confirmed by a separate study by the Canadian Internet Project, which found that more than any other country in the world, people in China see the Internet as giving them more say in government and more political power. By contrast, Americans are less than half as likely to say that.
In all, more than 100 million Chinese access the Internet, less than one-tenth the total population of 1.3 billion. Experts believe the country will soon surpasses the United States as having the most people online.
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