A coalition of 35 music publishers, prominently featuring Sony Music Publishing and Warner Chappell Music, has initiated legal proceedings in the U.S. District Court for the Northern District of California. They allege that AI firm Anthropic, along with its two co-founders, has illicitly utilized tens of thousands of copyrighted musical compositions. This was allegedly achieved through methods such as BitTorrent downloads and web crawling, with the intent to train its Claude large model and reap commercial benefits. The publishers assert that this constitutes one of the most significant and flagrant instances of intellectual property theft ever recorded, and are seeking a court injunction as well as billions of dollars in compensation. Anthropic, for its part, refutes all accusations and vows to mount a robust defense. Notably, the company has been embroiled in numerous copyright controversies in the past, including a $1.5 billion settlement with a consortium of writers. This latest lawsuit emerges as Anthropic gears up for a major initial public offering (IPO), casting a shadow of uncertainty over its listing plans.