Subscribers sue Anthropic, OpenAI, Google, SpaceXAI over "pacing" pact

What happened: Four paying AI subscribers filed a proposed class action, Buist et al. v. Anthropic PBC et al., in the US District Court for the Northern District of California on 18 September 2026.

The numbers: The named plaintiffs pay for Claude, and three of them also pay for ChatGPT, Grok and Gemini. They want to represent all US subscribers. Lead attorney is Nick Rowley.

Why it matters: The complaint says an agreement between competitors to slow product improvement counts as an unlawful restriction of output under Section 1 of the Sherman Act, even if each firm frames it as a safety move.

The context: The suit points to Anthropic chief executive Dario Amodei's 12 September essay, "We Must Pace the Frontier," which called for the industry to slow capability gains together. It claims OpenAI's Sam Altman, SpaceXAI's Elon Musk and Google DeepMind's Demis Hassabis signalled agreement that same day. It also cites a July statement referencing "intense competitive pressure not to unilaterally slow" down.

The catch: Plaintiffs say they have no objection to any single company slowing down on its own for safety reasons. Their claim targets only a joint decision among rivals.

In their words: The complaint states: "The antitrust laws do not permit competitors to decide among themselves that competition is too dangerous."

Who's affected: Paying subscribers to Claude, ChatGPT, Grok and Gemini, who the suit says were deprived of product improvements as a result of the alleged pact.

What's next: None of the four companies has responded publicly. The case arrives as Congress has stripped a related antitrust shield from a defence bill, while the Justice Department has indicated narrower cybersecurity cooperation between labs would not raise the same concerns, setting up a test of whether AI safety coordination can survive competition law.

Read more: ABC News