In October 2023 the music publishing companies Universal Music Group, Concord, and ABKCO filed a federal lawsuit against the artificial intelligence company Anthropic, accusing them of violating copyright law by using the lyrics to over 500 songs to train their chatbot. Now, a federal judge is ordering Anthropic to respond to allegations that they submitted a court filing containing a “hallucination” created by AI as part of its defense against those copyright claims, Reuters reports.