Sony Music Publishing, Warner Chappell Music and a collection of affiliated publishing companies filed the complaint on August 28 in the US District Court for the Northern District of California.
Anthropic is not the only defendant. CEO and co-founder Dario Amodei and co-founder Benjamin Mann are also personally named in the case.
The publishers allege copying on a massive scale
The complaint reaches far beyond a handful of Claude responses reproducing song lyrics. The publishers allege that Anthropic copied tens of thousands of copyrighted musical compositions while assembling material used to develop its models.
Works identified across the complaint and reporting around the case include songs associated with artists and catalogs ranging from Taylor Swift and Mariah Carey to Michael Jackson, Ain't No Mountain High Enough and Eye of the Tiger.
The plaintiffs accuse Anthropic of obtaining material through scraping, automated downloading, torrents and other sources they describe as unauthorized or pirated.
How the material was acquired could matter as much as training itself
The publishers also claim Claude has reproduced protected lyrics verbatim or nearly verbatim in some circumstances.
The larger legal argument, however, attacks the acquisition of the training material itself. That potentially separates part of this case from the narrower question of whether training a model on lawfully obtained copyrighted works can qualify as fair use.
If copyrighted files were pirated before they were used for model development, the court could have to address conduct occurring before the familiar AI-training argument even begins.
The damages calculation can become enormous
The publishers are seeking statutory damages of up to $150,000 for each work found to have been willfully infringed.
They are also seeking additional damages tied to alleged removal of copyright-management information, which can reach $25,000 per violation under the claims being asserted.
Those are requested statutory ceilings, not an amount Anthropic has been ordered to pay. No finding of infringement has been made.
With tens of thousands of works allegedly involved, however, the arithmetic explains why the lawsuit is being described as potentially worth billions of dollars.
All three major publishing groups are now fighting Anthropic
Anthropic was already facing a separate music-publishing case involving Universal Music Publishing Group, Concord and ABKCO.
Sony Music Publishing and Warner Chappell entering the fight means publishing businesses associated with all three global music majors are now litigating against the Claude developer.
The industry's position toward AI is not simply rejection. Warner has separately moved from litigation to licensed partnerships with AI music company Suno, illustrating the commercial alternative the labels and publishers increasingly want: permission, participation and payment.
Sony formally opted out of unauthorized AI training years ago
Sony Music Group publicly stated its position in May 2024. Unless specifically authorized, it prohibited text and data mining, scraping and similar use of Sony Music Entertainment and Sony Music Publishing content for training, developing or commercializing AI systems.
At the same time, Sony said it supported responsible uses of AI as a creative tool when artists and songwriters remained in control of their rights.
The argument has now moved from a rights reservation on a corporate website to federal court.
Anthropic says it will fight the claims
Anthropic rejects the publishers' allegations and says it intends to defend itself vigorously.
AI companies have generally argued that model training can be transformative, extracting patterns from source material rather than functioning as a substitute distribution system for the original works.
Publishers increasingly see the issue differently: a commercially valuable training corpus, they argue, should not be built from protected catalogs without permission simply because the resulting model is statistically different from the files that went into it.
That disagreement is now attached to some of the largest catalogs in the music business.
