Sony and Warner are suing Anthropic over lyrics in its AI

Sony Music Publishing and Warner Chappell Music have sued Anthropic, the maker of Claude, accusing it of a "brazen campaign of illegally torrenting, scraping, and downloading copyrighted works" to build its AI models. The suit was filed on 28 August 2026 in the US District Court for the Northern District of California, and it names two of Anthropic's co-founders, chief executive Dario Amodei and Benjamin Mann, as individual defendants.

Music publishers own the underlying compositions, including lyrics, rather than the recordings. The publishers describe the case as "one of the largest and most blatant ongoing thefts of intellectual property in history".

What the lawsuit claims

The heart of the complaint is piracy. According to Music Business Worldwide, the publishers allege that Mann used BitTorrent in June 2021 to download at least five million pirated books from Library Genesis, and that Anthropic staff torrented at least two million more from Pirate Library Mirror in July 2022. Both figures come from findings in an earlier case, Bartz v. Anthropic. TechCrunch reports the publishers say those books included ones containing lyrics and sheet music.

The complaint also alleges that Anthropic scraped lyrics from licensed sites including Musixmatch and LyricFind, ran a "destructive scanning" operation on second-hand books, and used datasets such as Common Crawl, The Pile and Books3. It says Claude reproduces lyrics in its outputs, and that guardrails added after earlier litigation can be bypassed by prompting again. Songs named in the filing include "Eye of the Tiger", "Ain't No Mountain High Enough" and Taylor Swift's "Paper Rings".

The publishers say tens of thousands of compositions were infringed. They seek up to $150,000 per wilfully infringed work, plus up to $25,000 for each alleged removal of copyright management information, as well as a jury trial, destruction of infringing copies and an accounting of Claude's training data. Music Business Worldwide notes that this could put Anthropic's statutory exposure in the multi-billion-dollar range.

Anthropic's response and the earlier cases

An Anthropic spokesperson told TechCrunch: "We disagree with the publishers' claims and we intend to defend ourselves robustly in court."

The piracy focus builds on Bartz v. Anthropic, a case brought by authors. TechCrunch says a judge in that case ruled that training on copyrighted works was legal but that acquiring the content through piracy was not, and Anthropic agreed to a $1.5 billion settlement with the authors in September 2025. The new complaint argues that sum is too small to deter infringement.

This is also not the first music case against the company. Universal Music Group, Concord and ABKCO sued Anthropic in October 2023 over roughly 500 songs, and the same publishers filed a second suit in January 2026 covering more than 20,000 works. BMG and Round Hill Music have since filed their own cases. Some of the lawyers representing Concord and UMG are also acting for Sony and Warner Chappell.

What it means for AI development

The case shows how rights holders have adapted after the Bartz ruling. Rather than arguing only that training itself infringes, which remains contested, the publishers are pressing on how the material was obtained and on what Claude produces when asked for lyrics.

For users, the practical effect may be AI assistants that are more cautious about reproducing lyrics. The longer-term question is whether cases like this push AI companies towards licensing deals with music publishers. The allegations have not yet been tested in court, and Anthropic says it will fight them.

Key takeaways

• Sony Music Publishing and Warner Chappell Music sued Anthropic on 28 August 2026 in the Northern District of California, also naming Dario Amodei and Benjamin Mann.
• The complaint centres on piracy, alleging torrenting of pirated books and scraping of lyrics sites to train Claude.
• It also alleges Claude reproduces lyrics and that its guardrails can be bypassed.
• The publishers seek up to $150,000 per wilfully infringed work across tens of thousands of compositions.
• Anthropic says it disagrees with the claims and will defend itself in court.