In a recent article in the Columbia Science and Technology Law Review, Mark A. Lemley, a professor at Stanford Law School, examines how generative AI challenges copyright law. Lemley explains that while traditional copyright law protects expression, not ideas, AI complicates this by generating expression from human prompts. He highlights the difficulty of proving copyright infringement when identical AI outputs can arise from different prompts. Lemley argues that courts should focus on whether someone saw and copied a prompt rather than output similarity. Lemley concludes that policymakers must either rethink copyright law or accept its diminishing relevance as AI creativity grows.