Sony Music Publishing, Warner Chappell Allege Anthropic Launched ‘Brazen Campaign’ to Illegally Train Claude on Copyrighted Songs in New Lawsuit

Two of the world’s largest music publishing houses have escalated their battle against artificial intelligence, filing a federal lawsuit in California that accuses Anthropic of orchestrating what they describe as a sweeping and deliberate campaign of copyright infringement. Sony Music Publishing and Warner Chappell Music lodged the complaint late Friday in the U.S. Northern District of California, naming the AI company, its CEO Dario Amodei, and co-founder Benjamin Mann as defendants. The 48-page filing alleges that Anthropic unlawfully used thousands of protected songs—from Marvin Gaye and Tammi Terrell’s classic “Ain’t No Mountain High Enough” to Mariah Carey’s holiday staple “All I Want for Christmas is You”—to train its Claude chatbot, a move the publishers call “a brazen campaign of illegally torrenting, scraping, and downloading copyrighted works on a massive scale.”

The legal action seeks to halt what the publishers term “blatant violation of copyright law,” requesting the court to block Anthropic’s training practices and award statutory damages of up to $150,000 for each infringed work. “These acts separately and together inflict immense harm on Music Publishers and the songwriters they proudly represent,” the attorneys argued. “Defendants can no longer hide their extraordinary theft, and their mass infringement is now well-documented.” Sony Music Entertainment and Warner Music Group, the parent companies behind the publishing arms, have taken a hard line here; a Warner Music spokesperson declined further comment, while Sony did not immediately respond to requests for clarification. Anthropic, for its part, dismissed the suit as “recycling allegations from cases already before the courts,” pointing to a prior ruling in Bartz v. Anthropic—a case that ended in a $1.5 billion settlement with authors—where a judge found training AI models on copyrighted material could qualify as transformative fair use, albeit not when the content is obtained through piracy. Notably, the same legal team representing the publishers also worked on that earlier authors’ case, signaling a coordinated legal strategy.

This lawsuit marks the latest twist in the music industry’s evolving relationship with generative AI, a sector that has seen companies oscillate between litigation and licensing as they grapple with its rapid rise. Anthropic, founded in 2021 by Amodei and Mann—both former OpenAI executives—has become a central figure in this debate, with its Claude models drawing scrutiny from creators across multiple fields. The new complaint follows a wave of similar actions: Concord Music Group and Universal Music Group have already sued, BMG filed its own case in March, and Round Hill Music took legal action just last month, all targeting Anthropic over alleged illegal scraping. These publishing battles run parallel to separate lawsuits against AI music generators Suno and Udio, where Warner Music Group has settled its claims, Universal has reached a deal with Udio while continuing to pursue Suno, and Sony Music remains locked in active litigation against both platforms. For songwriters and publishers, the stakes are existential—if AI firms can train on their work without compensation, the economic foundation of the industry could shift irreparably, a concern that legal experts say will only intensify as courts wrestle with how existing copyright law applies to machine learning.