Japan's Yomiuri Shimbun newspaper, one of the world's biggest by circulation, is suing U.S.-based AI firm Perplexity for allegedly "free-riding" on its content on its search engine. The lawsuit filed Thursday is one of a slew by media companies worldwide against AI firms using their material and is the first by a major Japanese news organization, Yomiuri said. It accuses Perplexity of "free-riding on the results of the activities of news organizations, which have invested a great deal of effort and expense." A spokesman for the paper added that this "could have a negative impact on accurate journalism ... and shake the foundations of democracy." The lawsuit filed in Tokyo seeks damages of 2.2 billion ( 14.7 million), equivalent to 120,000 Yomuiri articles used "without permission" between February and June.