The headline isn’t correct. This ruling is about a specific element of Fair Use, not a blanket declaration that copyrighted data cannot be used to train models as the headline suggests.

Fair Use requires some conditions be met. The one that wasn’t met here was that the work you’re creating can’t compete with the copyright owner.

From the Reuters article:

“Ross took the headnotes to make it easier to develop a competing legal research tool,” the judge said. “So ​Ross’s use is not transformative.”

In other cases, for example the Author’s Guild lawsuit against Meta/Anthropic/etc courts have ruled that using books to train LLMs is fair use because LLMs and books don’t compete.

They were required to pay for the books, but not prevented by copyright from using them to train a model.

There’s nothing novel happening in this case from a legal perspective. Maybe this is the first case where the defendant didn’t clear the elements of fair use but those elements predate AI by decades and have been uses in thousands of cases.