Sony Music and Warner Sue Anthropic for Billions Over AI Training Data

Quick Facts

• Sony Music Publishing and Warner Chappell Music filed a 48-page complaint in U.S. District Court in Northern California on Aug. 29, naming Anthropic and co-founders Dario Amodei and Benjamin Mann as defendants.
• The publishers seek up to $150,000 per work willfully infringed, with potential total damages reaching billions given the alleged theft of tens of thousands of copyrighted musical compositions.
• The suit builds on evidence from the Bartz v. Anthropic class action, which resulted in a $1.5 billion settlement approved in July 2026.

Sony Music Publishing and Warner Chappell Music sued Anthropic on Friday, accusing the Claude maker of running what they call a ‘brazen campaign of illegally torrenting, scraping, and downloading copyrighted works on a massive scale.’ The suit was filed in U.S. District Court for the Northern District of California.

The complaint names Anthropic, co-founder and CEO Dario Amodei, and co-founder Benjamin Mann as individual defendants. Songs cited in the filing include ‘Ain’t No Mountain High Enough,’ ‘All I Want for Christmas is You,’ ‘Eye of the Tiger,’ and ‘Paper Rings.’

The publishers allege Anthropic used tens of thousands of copyrighted musical compositions to train its Claude AI models without authorization. They seek statutory damages of up to $150,000 per willfully infringed work and up to $25,000 for each alleged removal of copyright management information.

The 48-page complaint brings four legal counts. Anthropic, Amodei, and Mann jointly face a count of direct infringement by torrenting. Amodei and Mann face an additional count of contributory infringement. Anthropic alone faces counts of direct infringement and removal or alteration of copyright management information.

The specific piracy allegations are detailed. The complaint states that in June 2021, Mann used BitTorrent to download at least five million pirated books from Library Genesis. Anthropic employees then torrented at least two million more from Pirate Library Mirror in July 2022.

The new suit draws heavily from the evidentiary record built in Bartz v. Anthropic, the authors’ class-action case in which a federal judge described Anthropic’s conduct as ‘straightforward piracy but at massive scale.’ That case settled for $1.5 billion, with final approval granted in July 2026. As part of that settlement, Anthropic agreed to destroy all original files obtained from Library Genesis and Pirate Library Mirror.

The publishers argued that any fair use defense tied to AI training does not apply here. Their position is that the act of torrenting itself constitutes a standalone act of infringement, regardless of what the downloaded material was used for.

With Sony and Warner now in litigation, the publishing arms of all three major music companies are suing Anthropic. Universal Music Publishing Group, Concord Music Group, and ABKCO filed suit in October 2023 over roughly 500 songs. Those same publishers filed a second case in January 2026 covering more than 20,000 works and seeking over $3 billion. BMG filed a third case in March 2026 over 493 compositions, and Round Hill Music filed a fourth on Aug. 17.

Music copyright adds structural complexity for AI defendants. A single commercially released song can contain multiple separately held copyrights covering lyrics, sound recordings, and compositions, each potentially owned by different parties. That structure opens AI companies to multiple lawsuits for the same underlying song.

For software and AI company executives, the pattern is clear. Courts in the Northern District of California have already accepted the foundational argument that training on pirated material is not a legitimate fair use defense. The Bartz settlement established a $1.5 billion data point. The music cases, covering tens of thousands of works with maximum statutory damages per work, carry the potential for far larger exposure.

Anthropic has not yet publicly responded to the Sony and Warner complaint.

Read more: Sony Music, Warner sue Anthropic, alleging a “brazen campaign” of intellectual property theft