Major music publishers, including units of Sony Music and Warner Music, have filed a substantial lawsuit against AI company Anthropic. The publishers accuse Anthropic of massive intellectual property theft, calling it one of the largest instances in history. The lawsuit alleges that Anthropic illegally torrented, scraped, and downloaded copyrighted musical works to train its "Claude" AI models. Defendants named in the 48-page complaint include Anthropic, CEO Dario Amodei, and co-founder Benjamin Mann. The plaintiffs are seeking significant damages, reportedly hundreds of thousands of dollars per infringed work. This legal action represents an early conflict in the ongoing battle over music rights and AI development. It is not the first time Anthropic has faced piracy allegations for its training data. Previously, the company settled a record $1.5 billion copyright case with authors and publishers in September 2025. The music industry has a history of aggressive legal action regarding copyright infringement. Anthropic has not yet responded to requests for comment on the new lawsuit.