Sony Music Publishing and Warner Chappell Music filed suit against Anthropic on August 28 in the U.S. District Court for the Northern District of California. Alongside the company, the complaint names co-founder and CEO Dario Amodei and co-founder Benjamin Mann as individual defendants.
The complaint opens by calling the conduct "one of the largest and most blatant ongoing thefts of intellectual property in history."
What the Complaint Says Anthropic Did
Plaintiffs lay out four ways Anthropic allegedly obtained the material. In June 2021, Mann downloaded more than 5 million pirated books via BitTorrent; in July 2022, Anthropic employees downloaded over 2 million more from Pirate Library Mirror. The second track was scraping content from licensed lyric sites such as MusixMatch and LyricFind. The third was "destructive scanning" of secondhand physical books. The fourth was drawing on public datasets including Common Crawl, The Pile, and Books3.
The allegedly infringed works are described as numbering in the "tens of thousands," with the complaint naming titles including "Ain't No Mountain High Enough," "All I Want for Christmas Is You," "Eye of the Tiger," "Livin' On a Prayer," "Hallelujah," "Uptown Funk," and Taylor Swift's "Paper Rings."
More damaging are the internal communications cited. Mann is alleged to have called Library Genesis "sketchy AF" in internal discussion; Anthropic's own Archive Team reportedly flagged the operation internally as a "blatant copyright violation"; and a 2024 planning document is quoted as saying, "We don't want it to be known that we are working on this." These materials come from documents unsealed in Bartz v. Anthropic, the authors' case in which the judge described Anthropic's conduct as "straightforward piracy but at massive scale."
Four Claims and the Damages Math
The complaint lists four causes of action: direct infringement through the torrent downloads, alleged against all three defendants; contributory infringement for the same conduct, alleged only against Amodei and Mann; direct infringement attributed to Anthropic alone; and removal or alteration of copyright management information (CMI).
Statutory damages run up to $150,000 per work for willful infringement, and up to $25,000 per CMI violation. A rough calculation using 20,000 works as a stand-in for "tens of thousands" puts the theoretical exposure on the first claim alone in the billions of dollars — plaintiffs are asking for a jury trial, destruction of infringing copies, and disclosure of what data went into training Claude.
A separate allegation targets Claude's output rather than its training data: plaintiffs say the model's guardrails are "easily circumventable by simply 're-prompting,'" and that Claude will still reproduce copyrighted lyrics in full. If that claim holds up, it shifts the case from a question of where the training data came from to one of a product that keeps generating infringing content.
Five Cases Now Form a Pattern
This is the fifth major copyright suit against Anthropic. In October 2023, Universal Music, Concord, and ABKCO sued over 500 songs, a case later moved to California; in January 2026, the same plaintiffs expanded their claims to more than 20,000 works, seeking over $3 billion; BMG followed in March with a suit over 493 works; Round Hill Music sued on August 17 seeking up to $1 billion; and eleven days later came Sony and Warner.
The reference point is the $1.5 billion class settlement Anthropic reached with authors in September 2025. Oppenheim + Zebrak, one of the law firms representing the plaintiffs, is also leading the parallel Concord/UMG case; the complaint's line that "Anthropic clearly considers that to be just the cost of doing business" is aimed squarely at that settle-and-move-on playbook.
With all three major music publishers now suing, the room for a quiet individual settlement has narrowed. Anthropic's valuation, per public reporting, sits around $2 trillion — enough to cover a payout. What's harder to resolve are the demands tied to the individual defendants and to disclosure of training data; if those push forward, what gets exposed won't just be a dollar figure.
Sources: complaint text, Music Business Worldwide, The Decoder, CocoLoop; the defendant list, four causes of action, statutory damages caps, and case sequence were checked against the complaint and press reports, and the damages exposure figure is the editor's rough estimate based on public numbers.