Sony and Warner Sue Anthropic Over Claude AI Training
Sony and Warner Chappell have sued Anthropic for allegedly training its Claude models on copyrighted lyrics, escalating the legal battle over intellectual property in generative AI.
On August 28, 2026, Sony Music Publishing and Warner Chappell Music filed a lawsuit in the US District Court for the Northern District of California against Anthropic, Chief Executive Officer Dario Amodei, and co-founder Benjamin Mann. The publishers accuse the defendants of copying tens of thousands of copyrighted musical compositions to train Anthropic’s Claude AI models. The lawsuit highlights famous songs such as Taylor Swift’s "Paper Rings," "September," "Hallelujah," and "Eye of the Tiger," characterizing the conduct as a massive theft of intellectual property.
The complaint details how Anthropic allegedly acquired the training data. In June 2021, Mann allegedly used BitTorrent to download five million pirated books from Library Genesis, and employees torrented another two million from Pirate Library Mirror in July 2022. These downloads reportedly contained hundreds of songbooks and sheet-music collections. Additionally, the publishers claim Anthropic scraped licensed lyric platforms like MusixMatch and LyricFind, ran a destructive scanning operation to digitize physical books, and utilized datasets like Common Crawl, The Pile, and Books3.
According to the filing, Anthropic engineers stripped copyright information from the texts before training. Consequently, Claude models can reproduce lyrics verbatim or generate derivative works in the style of specific songwriters, bypassing guardrails through simple re-prompting. The publishers point to evidence unsealed from a previous class-action lawsuit, Bartz v. Anthropic, which Anthropic settled for $1.5 billion in September 2025. In those documents, Mann allegedly described Library Genesis as "sketchy AF" in internal messages.
Represented by Oppenheim + Zebrak and Pryor Cashman, the publishers are demanding a jury trial. They seek statutory damages of up to $150,000 per willfully infringed work and up to $25,000 per violation for altering copyright management information. The plaintiffs also want the court to order the destruction of all infringing copies and demand a full accounting of Anthropic's training data and methods.
This is our own summary of reporting by Unite.AI
