Artificial intelligence developers won marginal legal battles this week when federal judges in California ruled that Anthropic (ANTH.PVT) and Meta (META) could "train" large language models (LLM) on copyrighted books.

But the larger war over AI developers' use of protected works is far from over.

Dozens of copyright holders have sued developers, arguing that the developers must pay rights holders before allowing generative AI software to interpret their works for profit. Rights holders also argue that the AI output cannot resemble their original works.

Rob Rosenberg, an intellectual property lawyer with Telluride Legal Strategies, called Tuesday's ruling siding with AI developer Anthropic a "ground-breaking" precedent, but one that should be viewed as an opening salvo.

"Judges are just starting to apply copyright law to AI systems," Rosenberg said, with many cases coming down the pike.

In that ruling, California US District Judge William Alsup said that Anthropic legally utilized millions of copyrighted books to train its various LLMs, including its popular chatbot Claude.

However, the judge distinguished books that Anthropic paid for from a pirated library of more than 7 million books that it also used to train Claude. As for the stolen materials, the judge said, Anthropic must face the plaintiff authors' claims that it infringed on their copyrights.

In a more limited ruling favoring Meta on Wednesday, California US District Judge Vince Chhabria said that a group of 12 authors who sued the tech giant, including stand-up comedian Sarah Silverman, made "wrong arguments" that prevented him from ruling on infringement. According to the authors, Meta used their copyrighted books to train its large language model Llama.

The rulings are among the first in the country to address emerging and unsettled questions over how far LLMs can go to rely on protected works.

"There is no predicting what's going to come out the other end of those cases," said Courtney Lytle Sarnow, an intellectual property partner with CM Law and adjunct professor at Emory University School of Law.

Sarnow and other intellectual property experts said they expect the disputes will end up in appeals to the US Supreme Court.

"I think it's premature for Anthropic and others like it to be taking victory laps," said Randolph May, president of the Free State Foundation and former chair of the American Bar Association's Administrative Law and Regulatory Practice section.

US copyright law, as defined by the Copyright Act, gives creators of original works an exclusive right to reproductions, distributions, and public performances of their material, according to Sarnow, including some derivative works and sequels to their original creations.