Sony Music and Warner Chappell Sue Anthropic — and Its Founders Personally — in Multi-Billion Dollar Lyrics Case

The last of the three major music publishing groups has now fired its shot at Anthropic. On Friday, August 28, 2026, Sony Music Publishing and Warner Chappell Music jointly filed a copyright infringement lawsuit against Anthropic PBC in the US District Court for the Northern District of California — and, in an aggressive twist, the complaint also names CEO Dario Amodei and co-founder Benjamin Mann as individual defendants. The publishers describe the alleged conduct as “one of the largest and most blatant ongoing thefts of intellectual property in history,” and the theoretical damages exposure runs into the multi-billion-dollar range.

News of the filing broke on August 29, drawing on the complaint obtained by Music Business Worldwide. Anthropic did not immediately respond to requests for comment, according to The Verge.

What the lawsuit alleges

The complaint identifies “tens of thousands” of the publishers’ musical compositions that Anthropic allegedly copied — not once, but “multiple times,” both as training inputs for the Claude model family and in the outputs those models generate. Among the specific songs named: Marvin Gaye and Tammi Terrell’s “Ain’t No Mountain High Enough,” Bon Jovi’s “Livin’ On a Prayer,” Earth, Wind & Fire’s “September,” Leonard Cohen’s “Hallelujah,” Mariah Carey’s “All I Want for Christmas is You,” and Taylor Swift’s “Paper Rings.”

The suit brings four counts:

1. Direct infringement by torrenting, against all three defendants;
2. Contributory infringement by torrenting, against Amodei and Mann personally;
3. Direct infringement, against Anthropic alone; and
4. Removal or alteration of copyright management information (CMI), against Anthropic alone.

The publishers are seeking statutory damages of up to $150,000 per willfully infringed work, plus up to $25,000 for each alleged removal of copyright management information. Multiply those figures across tens of thousands of compositions and the arithmetic lands squarely in the billions. Sony and Warner are also demanding a jury trial, destruction of all infringing copies, and a full accounting of Claude’s training data. They are represented by Oppenheim + Zebrak LLP — lead counsel in the Concord/UMG case against Anthropic — together with Pryor Cashman LLP.

The LibGen allegations, now aimed at executives

Much of the factual scaffolding comes from Bartz v. Anthropic, the authors’ class action in which another judge in the same district memorably described Anthropic’s conduct as “straightforward piracy but at massive scale.” That case ended in a $1.5 billion settlement that won final court approval on July 23, 2026.

The new complaint leans on evidence unsealed in Bartz to make its most pointed claims against the founders personally. It alleges that in June 2021, co-founder Benjamin Mann used BitTorrent to download at least five million pirated books from Library Genesis (LibGen), and that Anthropic employees torrented at least two million more from Pirate Library Mirror (PiLiMi) in July 2022. Internal messages cited in the filing include Mann’s own description of LibGen as “sketchy AF,” while Anthropic’s internal Archive Team reportedly called the site “a blatant violation of copyright.” On the book-scanning program, the complaint quotes a 2024 Anthropic planning document: “We don’t want it to be known that we are working on this.”

The publishers further allege that Anthropic scraped lyrics from licensed services such as MusixMatch and LyricFind — platforms that paid for their licenses — and that 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.”

All three majors are now litigating

With Sony and Warner joining, the publishing arms of all three major music companies are now simultaneously suing Anthropic over Claude’s training data:

• Universal Music Publishing Group, Concord, and ABKCO sued in Nashville in October 2023 over roughly 500 songs (the case was later transferred to California). The same publishers filed an amended complaint in January 2026 covering more than 20,000 works and seeking over $3 billion. Anthropic’s summary judgment motion in that case remains pending, with recent docket activity through August 20, 2026.
• BMG filed a third case in March 2026 over 493 compositions.
• Round Hill Music filed a fourth on August 17, 2026 — targeting both Anthropic and Suno, with claims of up to $1 billion apiece and, notably, no intention to settle.

The new Sony/Warner filing is strategically distinct in two ways. First, it is the first to pursue the founders’ personal assets, raising the stakes for Anthropic’s leadership beyond the corporate balance sheet. Second, it arrives weeks after the $1.5 billion authors’ settlement won approval — a result that appears to have emboldened rights holders and given their counsel a validated playbook of unsealed internal evidence to draw from.

Why this matters beyond music

The case lands at a moment when the legal ground under AI training data is shifting fast. The Bartz settlement established that mass-torrenting of copyrighted books carries a real price — $1.5 billion in that instance — and the publishers’ continued filings suggest the music industry sees a similar path. Statutory damages for willful infringement are the industry’s weapon of choice here precisely because they scale with the number of works, not with Anthropic’s actual profits or proven use of any specific lyric.

The personal-liability angle is the genuinely novel legal territory. If the court allows claims against Amodei and Mann as individuals to proceed, it would set a precedent that reaches into every AI startup: founders could be held personally accountable for data-acquisition decisions made in a company’s earliest days. Corporate shields exist to encourage risk-taking, but judges have historically been willing to pierce them when individuals are alleged to have personally directed infringing conduct — and “I torrented five million books myself” is exactly the kind of allegation that tests that line.

For Anthropic, the timing is uncomfortable. The company is reportedly preparing for what would be one of the largest IPOs in tech history, and litigation overhang measuring in the billions — with founders named as defendants — is precisely the kind of risk factor that complicates a public offering. The company is simultaneously fighting fair-use battles on multiple fronts, having recently won a procedural victory over the Pentagon’s supply-chain risk label even as these copyright cases accumulate.

For the broader industry, the pattern is clear: rights holders have moved past the exploratory phase. They are filing systematically, in parallel, across jurisdictions and creative sectors, using evidence unearthed in discovery to bring successive waves of claims. Whether fair use ultimately protects AI training — the core legal question Anthropic has staked its defense on — may now be decided not in the abstract, but case by case, with escalating settlement values marking the price of admission.