A group of music publishers, including Concord Music Group and Universal Music Group, has filed a $3 billion lawsuit against Anthropic, accusing the AI company of engaging in “flagrant piracy” by illegally downloading more than 20,000 copyrighted musical works. The alleged infringement includes sheet music, lyrics, and original compositions used to train Anthropic’s AI models, particularly its Claude series. The lawsuit, filed on Wednesday, marks one of the largest non-class action copyright cases in U.S. history. It was brought by the same legal team behind the high-profile Bartz v. Anthropic case, in which authors sued Anthropic for using their books and writings to train AI models. In that case, Judge William Alsup ruled that using copyrighted material for training AI is legal under fair use, but he emphasized that acquiring such content through illegal means—such as unauthorized downloads—violates copyright law. While the Bartz case resulted in a $1.5 billion settlement, with individual authors receiving roughly $3,000 per work for about 500,000 titles, the amount was seen as relatively minor for a company valued at $183 billion. The music publishers’ new case stems from an expansion of their initial claims. Originally, they had sued Anthropic over the use of around 500 copyrighted songs. However, during discovery in the Bartz case, they uncovered evidence that Anthropic had illegally downloaded thousands of additional works via torrent networks. The publishers attempted to amend their original lawsuit to include these new allegations, but a federal court denied the motion in October, citing their failure to pursue the piracy claims earlier. In response, they launched this separate legal action, which also names Anthropic CEO Dario Amodei and co-founder Benjamin Mann as individual defendants. The complaint accuses Anthropic of presenting itself as a leader in AI safety and research while building its business on widespread copyright infringement. “While Anthropic misleadingly claims to be an AI ‘safety and research’ company, its record of illegal torrenting of copyrighted works makes clear that its multibillion-dollar business empire has in fact been built on piracy,” the lawsuit states. Anthropic has not publicly responded to requests for comment on the new allegations.