Lawsuit Alleges AI Companies Illegally Agreed to Slow Development

Four paying subscribers have filed a federal lawsuit against artificial intelligence companies Anthropic, OpenAI, Google, and xAI, alleging that their public pledge to slow AI development constitutes an illegal agreement in violation of antitrust laws. The lawsuit, filed on September 18, 2026, in the U.S. District Court for the Northern District of California, was brought by plaintiffs including Christine Bullock, who pay for subscriptions to services like Claude, ChatGPT, Grok, and Gemini. They are seeking to represent a nationwide class of paid subscribers and are asking the court for class certification, an injunction blocking further coordination, and a declaration that the companies broke the law. The legal action stems from an essay published on September 12, 2026, by Anthropic CEO Dario Amodei, titled "We Must Pace the Frontier," which called on rival labs to coordinate slowing the release of increasingly powerful AI systems in the name of safety. On the same day, OpenAI CEO Sam Altman, xAI CEO Elon Musk, and Google DeepMind cofounder Demis Hassabis publicly endorsed Amodei's proposal.