A copyright clash over song lyrics now reaches into Anthropic’s founding team. Sony Music Publishing and Warner Chappell Music filed a complaint on August 28 that pulls chief executive Dario Amodei and co-founder Benjamin Mann into a case over Claude’s training data, with tens of thousands of compositions at stake. The case is docketed in the US District Court for the Northern District of California.
The publishers call the conduct one of the largest and most blatant thefts of intellectual property in history. Works named in the filing range from All I Want for Christmas is You to Taylor Swift’s Paper Rings. Underlying the claims is an accusation of mass downloading: Mann allegedly used the BitTorrent protocol in June 2021 to pull at least five million pirated books from Library Genesis, employees followed with two million more from Pirate Library Mirror in July 2022, and songbooks and sheet-music collections came along in those hauls. Amodei, the publishers say, expressly authorized it.
Four counts follow. Direct infringement through torrenting heads the list, then contributory infringement leveled at Amodei and Mann personally, then scraping, destructive scanning, model training and outputs, and finally removal of copyright management information. The complaint argues guardrails meant to stop Claude reproducing lyrics are easily bypassed by re-prompting, and that the model’s new lyrics compete with the publishers’ catalogs and dilute royalty pools.
The case rests heavily on Bartz v. Anthropic, the authors’ class action in the same district. A court there called the behavior straightforward piracy at massive scale, and Anthropic settled it in September 2025 for $1.5B. The new filing demands up to $150K per work in statutory damages, $25K for each stripped copyright notice, supervised destruction of infringing copies, and a full accounting of training data. Anthropic had not publicly responded.
