US Judge Sides with Anthropic in AI Copyright Case

Published Date : 25/06/2025 

A US judge has ruled that using books to train AI software does not violate US copyright law, but Anthropic will still face trial over its use of pirated copies. 

A US judge has ruled that using books to train artificial intelligence (AI) software is not a violation of US copyright law. The decision came out of a lawsuit brought last year against AI firm Anthropic by three authors, including best-selling mystery thriller writer Andrea Bartz, who accused it of stealing her work to train its Claude AI model and build a multi-billion dollar business.

In his ruling, Judge William Alsup said Anthropic's use of the authors' books was 'exceedingly transformative' and therefore allowed under US law. However, he rejected Anthropic's request to dismiss the case, ruling the firm would have to stand trial over its use of pirated copies to build its library of material.

Bringing the lawsuit alongside Ms Bartz, whose novels include We Were Never Here and The Last Ferry Out, were non-fiction writers Charles Graeber, author of The Good Nurse: A True Story of Medicine, Madness and Murder, and Kirk Wallace Johnson, who wrote The Feather Thief. Anthropic, a firm backed by Amazon and Google's parent company, Alphabet, could face up to $150,000 in damages per copyrighted work. The firm holds more than seven million pirated books in a 'central library' according to the judge.

The ruling is among the first to weigh in on a question that is the subject of numerous legal battles across the industry - how Large Language Models (LLMs) can legitimately learn from existing material. 'Like any reader aspiring to be a writer, 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,' Judge Alsup wrote. 'If this training process reasonably required making copies within the LLM or otherwise, those copies were engaged in a transformative use,' he said. He noted that the authors did not claim that the training led to 'infringing knockoffs' with replicas of their works being generated for users of the Claude tool. If they had, he wrote, 'this would be a different case'.

Similar legal battles have emerged over the AI industry's use of other media and content, from journalistic articles to music and video. This month, Disney and Universal filed a lawsuit against AI image generator Midjourney, accusing it of piracy. The BBC is also considering legal action over the unauthorised use of its content. In response to the legal battles, some AI companies have responded by striking deals with creators of the original materials, or their publishers, to license material for use. Judge Alsup allowed Anthropic's 'fair use' defence, paving the way for future legal judgements.

However, he said Anthropic had violated the authors' rights by saving pirated copies of their books as part of a 'central library of all the books in the world'. In a statement, Anthropic said it was pleased by the judge's recognition that its use of the works was transformative, but disagreed with the decision to hold a trial about how some of the books were obtained and used. The company said it remained confident in its case and was evaluating its options. A lawyer for the authors declined to comment. 

Frequently Asked Questions (FAQS): 

Q: What is the main issue in the lawsuit against Anthropic?

A: The main issue is whether Anthropic's use of copyrighted books to train its AI model constitutes a violation of US copyright law.

Q: What did Judge Alsup rule in favor of?

A: Judge Alsup ruled that Anthropic's use of the authors' books was 'exceedingly transformative' and allowed under US law, but the firm will still face trial over the use of pirated copies.

Q: How much in damages could Anthropic face?

A: Anthropic could face up to $150,000 in damages per copyrighted work.

Q: What is the significance of this ruling in the AI industry?

A: This ruling is significant as it is one of the first to address the legality of using existing material to train AI models, which is a topic of numerous legal battles in the industry.

Q: What are other companies doing in response to similar legal challenges?

A: Some AI companies are striking deals with creators or publishers to license material for use, while others are facing lawsuits from media giants like Disney and Universal. 

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