IP Law Daily, COPYRIGHT—N.D. Cal.: Sony and Warner join the list of music publishers in suing Anthropic, (Sep 1, 2026)

By Matthew Hersh, J.D.

The AI giant allegedly torrented music lyrics and generated “verbatim copies” of them in response to user queries.

Anthropic and its two founders have “conducted a brazen campaign of illegally torrenting, scraping, and downloading copyrighted works on a massive scale” in order to develop the Claude series of artificial intelligence, a new federal lawsuit contends. The lawsuit, brought in the Northern District of California by Sony Music Publishing and Warner Chappell Music, builds upon the findings in earlier litigation against Anthropic by book publishers and adds the two companies to the growing list of music publishers to take on Anthropic over copyright as well as DMCA violations (Sony Music Publishing (US) LLC v. Anthropic PBC, No. 5:26-cv-09217 (N.D. Cal. Aug. 28, 2026)).

The context for the lawsuit is the Bartz v. Anthropic litigation, also pending in the same district. In that case, which was brought as a class action by book publishers and authors, the court found that Anthropic had illegally downloaded seven million copyrighted books from online pirate websites such as Library Genesis and Pirate Library Mirror. That case ended up in a historic $1.5 billion settlement, which has been approved by the court and is currently in the process of being paid out.

But while the settlement resolved Anthropic’s dispute with book publishers and authors, it did not settle the dispute with songwriters and music publishers. Included in the mass of written material that Anthropic allegedly downloaded from pirate libraries, the music publishers contend, were books containing the lyrics and sheet music to “hundreds or more” of the publishers’ copyrighted musical compositions, including well-known works like “Livin’ On a Prayer,” “September,” “Great Balls of Fire,” “Ramblin’ Man,” and “Hallelujah.” In addition, the complaint alleges, Anthropic also unlawfully gathered material by using webcrawlers to scrape lyrics from authorized lyric-display websites, “destructively scanning” millions of second-hand copies of books, and downloading the contents of other third-party datasets.

In addition to downloading copyright works without permission, the lawsuit contends, Anthropic has also allegedly committed further copyright violations by keeping the material in its databases, creating so-called “data mixes” for internal training purposes, repeatedly using it to train new models, and allegedly “routinely generat[ing] verbatim copies of the lyrics” to the publishers’ musical compositions in response to user prompts. And by including those works in the training data for Claude, the lawsuit contends, Anthropic “knowingly enables Claude to not only reproduce verbatim copies and AI-generated derivatives of [the publishers’] lyrics to users upon a user’s request, but to also generate market substitutes capable of directly competing with [the publishers’] works.”

The lawsuit also alleges that Anthropic intentionally removed and altered the music publishers’ copyright management information in violation of the Digital Millennium Copyright Act. “After unlawfully harvesting” the publishers’ works, the lawsuit contends, “Anthropic processes the text from those works to remove repetitive ‘garbage’ portions that it does not want to use in training its models and with the knowledge and purpose of concealing its other infringements.” Anthropic’s removal of this information denies the publishers of valuable attribution, the lawsuit contends, “including when its Claude models generate verbatim reproductions of [the publishers’] works without appropriate acknowledgment in response to user prompts.”

Sony and Warner now round out the list of music publishers to take on Anthropic over its alleged infringement of musical compositions. A coalition of music publishers led by Universal Music Publishing, Concord Music, and ABKCO Music sued Anthropic in January of this year, while prominent indie publisher and record label Round Hill Music joined the fray earlier this month. In addition to naming Anthropic, the Sony and Warner lawsuit also names as individual defendants company founders Dario Amodei and Benjamin Mann.

The Case is No. 5:26-cv-09217.

Attorneys: Benjamin S. Akley (Pryor Cashman LLP) for Sony Music Publishing [US] LLC.

Companies: Sony Music Publishing (US) LLC; Anthropic PBC

Cases: Copyright CaliforniaNews AINews