A judge’s decision that Anthropic‘s use of copyrighted books to train its AI models is a “fair use” is likely only the start of lengthy litigation to resolve one of the most hotly contested questions over the latest tech revolution.

A federal judge in California has issued a complicated ruling in one of the first major copyright cases involving AI training, finding that while using books to train AI models constitutes fair use, downloading pirated books was a violation of copyright.

However, the judge simultaneously ordered the company to face trial this December for allegedly building a "central library" containing over 7 million pirated books, a decision