Author Arthur Kleiner files second copyright class action against Adobe over SlimLM/SlimPajama training

What happened: On February 9, 2026, author Arthur Kleiner filed a second proposed copyright class action against Adobe Inc. in the U.S. District Court for the Northern District of California (Case No. 5:26-cv-01218), represented by Bursor & Fisher. Kleiner, a New York author of books including The Age of Heretics, advances the same theory as the December 2025 Lyon suit: that Adobe downloaded, copied, stored and used the SlimPajama dataset — via Common Crawl and RedPajama, which includes material from the Books3 corpus — to train its SlimLM small language models, without authorization or compensation. The complaint cites Bartz v. Anthropic on the piracy question. On March 9, 2026, the court deemed Kleiner related to the Lyon action, finding both cases assert the same direct-infringement claim against Adobe over the same dataset and models, and seek the same relief.