A group of publishers and author Scott Turow filed a class action lawsuit on Tuesday against Meta and its CEO Mark Zuckerberg, claiming that the tech giant illegally downloaded millions of copyrighted books and then used the works to train its AI model Llama.

The lawsuit, filed in U.S. District Court in New York, claims that Meta had approached publishers to license works, but on Zuckerberg’s “personal instruction,” they abandoned those negotiations “and stole the works instead.”

“That path was more expedient for Meta, but it deprived publishers and authors of fair compensation and spurned established licensing markets,” the lawsuit stated.

The lawsuit is only the latest litigation over the use of copyrighted works in AI models, something that tech companies have generally argued is a “fair use” under the Copyright Act. The plaintiffs in the case are Turow, Elsevier, Cengage Learning, Hachette Book Group, Macmillan Publishing Group and McGraw Hill.

A Meta spokesperson said, “AI is powering transformative innovations, productivity and creativity for individuals and companies, and courts have rightly found that training AI on copyrighted material can qualify as fair use. We will fight this lawsuit aggressively.”

The publishers claim that the unauthorized use of their works threatens their business models, with Llama able to produce “verbatim and near-verbatim copies, replacement chapters of academic textbooks, summaries and alternative versions of famous novels and journal articles, inferior knockoffs that copy creative elements of original works, and derivative works exclusively reserved to rights holders. Llama even tailors outputs to mimic the expressive elements and creative choices of specific authors.”

The lawsuit presents examples, pointing to Llama’s production of a “passable knockoff” of Sylvia Day’s One with You. The lawsuit also pointed to a flourishing market on Amazon for AI-generated books, noting that one writer “released three books in three months and accidentally left in the published text an AI prompt asking it to ‘rewrite’ passages ‘to align more with’ the work of a specific, published author identified by name.”

The lawsuit seeks unspecified monetary damages and a ruling barring Meta from the unauthorized use of the works, as well as an accounting of which material was used.

Last year, a federal judge sided with Anthropic in ruling that the AI company’s use of copyrighted books for its training models was a fair use. But the judge also ruled that the company still had to face a trial over its downloading millions of pirated books in digital form off the internet, something it had to do in order to train its models. Anthropic later reached a $1.5 billion class action settlement.