Sony and Warner Sue Anthropic in at Least Fifth Major Music IP Case

Sony Music Publishing and Warner Chappell filed a multi-billion dollar lawsuit against Anthropic, alleging the company illegally copied thousands of copyrighted musical compositions to train its Claude AI model. The suit is at least the fifth major music publisher action against Anthropic, following cases from Universal Music Publishing Group, Concord, and ABKCO in 2023; a second suit covering more than 20,000 works seeking $3 billion in January 2026; a BMG case over 493 compositions in March 2026; and a Round Hill Music filing on August 17, 2026. Plaintiffs seek up to $150,000 per willfully infringed work and up to $25,000 per alleged removal of copyright management information. The complaint cites internal Anthropic staff chats referencing Z-Library as evidence, alleges co-founder Benjamin Mann discussed acquiring LibGen pirated data with CEO Dario Amodei, who approved torrenting it, and claims human reviewers during Claude finetuning rewarded accurate reproductions of copyrighted lyrics over inaccurate ones. The suit also alleges pirated material indirectly reached commercial Claude models through synthetic data and reinforcement feedback from earlier Anthropic models trained on that material. Anthropic previously settled with authors for $1.5 billion after admitting to pirating more than 7 million books; the music publishers argue that sum is insufficient to deter a company with a projected $2 trillion valuation tied to an expected IPO.