The harsh criticism from Reporters Without Borders marks the latest instance in which a prominent high-tech company has faced accusations of cooperating with Chinese authorities to gain favor in a country that's expected to become an Internet gold mine. Sunnyvale, Calif.-based Yahoo and two of its biggest rivals, Google Inc. and Microsoft Corp.'s MSN, previously have come under attack for censoring online news sites and Web logs, or blogs. Reporters Without Borders ridiculed Yahoo for becoming even cozier with the Chinese government by becoming a police informant in a case that led to the recent conviction of Chinese journalist Shi Tao. "Does the fact that this corporation operates under Chinese law free it from all ethical considerations? How far will it go to please Beijing?" Reporters Without Borders said court papers showed that Yahoo Holdings (Hong Kong) Ltd. gave Chinese investigators information that helped them trace a personal Yahoo e-mail allegedly containing state secrets to Tao's computer. Yahoo Holdings (Hong Kong) Ltd. is part of Yahoo's global network. Shi, a former journalist for the financial publication Contemporary Business News, was sentenced in April to 10 years in prison for illegally providing state secrets to foreigners.