Anthropic sued for illegally training Claude on Stanford professors' works
What's the story
Anthropic, a leading player in the artificial intelligence (AI) space, has been accused of illegally using the works of over 10 Stanford University professors to train its Claude models. The allegation was made in a May 2026 lawsuit and later confirmed by a federal judge. Among those whose work was allegedly used without permission are Professors Tobias Wolff, Abraham Verghese, Chang-Rae Lee, Daniel Mason, Hayagreeva Rao, and Myra Strober.
Legal perspective
Judge's ruling on 'fair use' in Bartz v/s Anthropic
In the case of Bartz v. Anthropic, Judge William Alsup ruled that while Anthropic could no longer use pirated books to create a permanent central library, the legal acquisition of books for training Claude's Large Language Models (LLMs) was fair use.
He compared AI training to human reading and internalizing a book's themes and style.
"Anthropic's LLMs trained upon works not to race ahead and replicate or supplant them, but to turn a hard corner and create something different."
Author concerns
Wolff calls settlement 'slave labor'
The case led to a $1.5 billion settlement for authors and publishers of nearly 500,000 registered works. However, Wolff and 27 other authors have expressed dissatisfaction with the settlement amount.
Wolff, who is a professor emeritus of English and winner of the National Medal of Arts, said, "To put me to work that way, without remittance, is a form of slave labor."
He added that they are using his work without paying for it.
Legal action
Wolff and Lee file separate lawsuit against Anthropic
Wolff and English professor Chang-Rae Lee have opted out of the Bartz settlement.
They have filed a separate non-class lawsuit, Cruz v. Anthropic, seeking a jury trial for full statutory damages of up to $150,000 per infringed work.
This is much higher than the approximate $3,000 of damages per work offered in the Bartz settlement.
The plaintiffs allege that Anthropic illegally downloaded their copyrighted books from "shadow libraries" like LibGen and PiLiMi.
Guild actions
Authors Guild pursuing similar lawsuits against other AI companies
The Authors Guild is also pursuing other lawsuits, including one against OpenAI and Microsoft.
The guild's CEO Mary Rasenberger said these are part of a "multi-pronged approach to ensure that the law is clear that AI companies must license the books they use."
She added, "Licensing allows authors and publishers to be compensated and to require the use of filters that ensure their works do not appear in outputs unless separately licensed."