Author Elizabeth Lyon files copyright class action against Adobe over SlimLM models trained on SlimPajama/Books3

What happened: On December 16, 2025, author Elizabeth Lyon filed a proposed copyright class action against Adobe Inc. in the U.S. District Court for the Northern District of California (Case No. 5:25-cv-10732). The complaint alleges Adobe trained its SlimLM small language models — models Adobe describes as optimized for document-assistance tasks on mobile devices — on the SlimPajama pre-training dataset, which it traces back through RedPajama to the Books3 corpus of pirated books. The plaintiff, an Oregon author, alleges Adobe downloaded, stored, processed and retained copies of copyrighted books without authorization as part of SlimLM's pre-training process, and seeks damages on behalf of a proposed class of copyright owners whose works were allegedly included. Adobe had not publicly commented on the suit at the time of reporting. This was the first major AI-training copyright case filed against Adobe.