Meta has won a copyright lawsuit brought by a group of authors who accused the company of using their books without permission to train its Llama generative AI.

A US federal judge in San Francisco ruled the AI training was 'transformative' enough to qualify as fair use under copyright law.

Judge Vince Chhabria noted, however, that future claims could be more successful. He warned that using copyrighted books to build tools capable of flooding the market with competing works may not always be protected by fair use, especially when such tools generate vast profits.

The case involved pirated copies of books, including Sarah Silverman's memoir 'The Bedwetter' and Junot Diaz's award-winning novel 'The Brief Wondrous Life of Oscar Wao'. Meta defended its approach, stating that open-source AI drives innovation and relies on fair use as a key legal principle.

Chhabria clarified that the ruling does not confirm the legality of Meta's actions, only that the plaintiffs made weak arguments. He suggested that more substantial evidence and legal framing might lead to a different outcome in future cases.