Thomson Reuters won a significant legal battle against Ross Intelligence, a company that utilized Westlaw's headnotes to train its AI model for legal case summarization. The court ruled that Ross's practices constituted unauthorized copying and competition against Westlaw, as the intent was to create a market substitute. This case highlights the importance of fair use definitions in AI training, especially concerning existing copyrighted materials. While the ruling focuses on non-generative AI, it raises concerns for AI companies about future applicability and challenges related to copyright and competition. The case suggests that substantial copyright violations might be necessary for training AI systems, igniting debates over ownership, fair compensation for creators, and the potential need for regulatory changes.