Two writers have filed a class - action copyright lawsuit against OpenAI, accusing the company of using their books to train ChatGPT without authorization. The plaintiffs' tests showed that when asked to summarize the books involved in the case, ChatGPT could generate relatively accurate summaries, indicating that the defendant obtained the books involved in the case and used them for model training. The plaintiffs have made six accusations, including direct copyright infringement, vicarious copyright infringement, violation of the provisions on copyright management information in the DMCA, unfair competition, negligent infringement, and unjust enrichment. This case has sparked discussions on the issue of copyright liability allocation for the training and output content of large language models.