Sony Music Publishing and Warner Chappell Music have filed a copyright infringement suit against Anthropic in the United States, alleging that the company behind the Claude artificial intelligence models carried out what the publishers call one of the largest ongoing thefts of intellectual property in history.
The complaint, filed Friday (August 28) in the United States District Court for the Northern District of California, also names Anthropic co-founder and chief executive Dario Amodei and co-founder Benjamin Mann as individual defendants.
With the new filing, the publishing arms of all three major music companies are now litigating against Anthropic.
Existing publisher litigation#
Universal Music Publishing Group, Concord Music Group, and ABKCO first sued in Nashville in October 2023 over roughly 500 songs; that case was later transferred to California.
- The same publishers filed a second suit in January 2026 covering more than 20,000 works and seeking over USD $3 billion.
- BMG brought a third case in March 2026 over 493 compositions.
- Round Hill Music filed a fourth case on August 17.
Sony and Warner are seeking statutory damages of up to $150,000 per work willfully infringed, plus up to $25,000 for each alleged removal of copyright management information.
“Among the innumerable copyrighted works Defendants illegally harvested to fuel Claude are thousands upon thousands of Music Publishers’ copyrighted musical compositions, including such beloved songs as “Ain’t No Mountain High Enough,” “All I Want for Christmas is You,” “Eye of the Tiger,” “Here Comes Santa Claus,” and “Paper Rings.” In blatant violation of copyright law, Defendants have unlawfully acquired troves of Music Publishers’ musical compositions, and then systematically copied those works multiple times, including as the inputs to train Anthropic’s Claude AI models and in the outputs those models generate.”
The complaint identifies “tens of thousands” of the publishers’ allegedly infringed compositions, a characterization that would place Anthropic’s theoretical statutory exposure in the multi-billion-dollar range.
Claims and demands#
Sony Music Publishing (SMP) and Warner Chappell Music (WCM) are demanding a jury trial. They are represented by Oppenheim + Zebrak, LLP, lead counsel for the Concord and Universal Music Publishing Group case against Anthropic, and by Pryor Cashman LLP.
The publishers also demand that all infringing copies of the works be destroyed and that Anthropic supply an account of Claude’s training data.
The suit brings four counts:
- Direct infringement by torrenting, against all three defendants
- Contributory infringement by torrenting, against Amodei and Mann
- Direct infringement, against Anthropic alone
- Removal or alteration of copyright management information, against Anthropic alone
Torrenting and training data allegations#
The complaint alleges that in June 2021, Mann used BitTorrent to download at least five million pirated books from Library Genesis, and that Anthropic employees torrented at least two million more from Pirate Library Mirror in July 2022.
Both figures are drawn from findings in Bartz v. Anthropic, the authors’ case in which another judge in the same district described Anthropic’s conduct as “straightforward piracy but at massive scale.”
“Dr. Amodei and Mr. Mann are personally liable for their respective roles in this illegal torrenting of pirated copies of Music Publishers‘ works from LibGen and PiLiMi,” the complaint states.
The filing cites internal Anthropic material unsealed in Bartz, including Mann’s description of LibGen as “sketchy AF.” It also states that Anthropic’s own Archive Team had described LibGen as a “blatant violation of copyright.”
“[we] bring this action to hold accountable the culprits behind one of the largest and most blatant ongoing thefts of intellectual property in history. Defendants Anthropic and its founders Dario Amodei and Benjamin Mann have conducted a brazen campaign of illegally torrenting, scraping, and downloading copyrighted works on a massive scale in order to develop, operate, and reap enormous profits from Anthropic’s “Claude” series of artificial intelligence (“AI”) models.”
The publishers further allege that Anthropic scraped lyrics from licensed sites including MusixMatch and LyricFind, ran a “destructive scanning” operation on second-hand books, and used Common Crawl, The Pile, and Books3.
On Books3, the complaint says Mann downloaded pirated books “to avoid the trouble of paying for them, hoping they might prove useful for training large language models (LLMs) or something else,” quoting Bartz.
On the scanning, it quotes a 2024 Anthropic planning document unsealed in Bartz: “We don’t want it to be known that we are working on this.”
The publishers further allege that Claude reproduces their lyrics verbatim in outputs, and that guardrails added after earlier litigation from Universal Music Publishing Group, Concord, and ABKCO are “easily circumventable by simply ‘re-prompting’” the model.
Songs named in the filing#
Song titles named in the body of the filing as being allegedly infringed include “Ain’t No Mountain High Enough,” “All I Want for Christmas is You,” “Eye of the Tiger,” “Livin’ On a Prayer,” “September,” “Hallelujah,” “Uptown Funk,” and Taylor Swift’s “Paper Rings.”
Book authors settlement#
The complaint leans heavily on Anthropic’s $1.5 billion settlement with book authors, agreed in September 2025 over the same torrenting conduct.
“But Anthropic clearly considers that to be just the cost of doing business given that its entire business model continues to be built on copyright theft,” it states.
