Four paying subscribers to AI chatbots have filed a proposed class action against Anthropic, OpenAI, Google, and SpaceXAI in the U.S. District Court for the Northern District of California. They allege that the four companies unlawfully agreed to slow AI development after Anthropic’s chief executive called for industry coordination on September 12, 2026. The court has issued summonses, and no defendant has yet responded.
Latest development Sep 19, 2026
In September 2026, four paying AI chatbot subscribers filed a proposed class action in the U.S. District Court for the Northern District of California. They allege that Anthropic, OpenAI, Google, and SpaceXAI conspired to slow AI development in violation of the Sherman Act. The suit was filed on September 18 or 19, 2026, and no defendant has yet responded.
Why it matters
The case will test whether public calls among rival AI labs for coordinated safety “slowdowns” can amount to per se unlawful collusion under the Sherman Act. The outcome affects four major AI developers and any future industry coordination on the pace of AI development.
Background
On September 18, 2026, four paying subscribers to AI chatbots filed a proposed class action against Anthropic PBC, OpenAI, SpaceXAI LLC, and Google LLC. They filed in the San Francisco Division of the U.S. District Court for the Northern District of California (Case No. 3:26-cv-10693). SpaceXAI is the entity through which Elon Musk now controls the former X.AI business. The named plaintiffs are Florida attorneys Charles Buist and Nick Spetsas and California residents Cheyenne Hunt and Christine Bullock. Each pays for a subscription to one of the defendants’ main consumer products: ChatGPT, Claude, Grok, or Gemini.
The complaint alleges that the four companies violated Section 1 of the Sherman Act by agreeing to slow the pace at which their competing AI products improve. The plaintiffs trace the alleged agreement to an essay that Anthropic chief executive Dario Amodei published on September 12, 2026. The essay called for industry-wide coordination to “pace the frontier” on safety grounds. Within hours, Elon Musk, OpenAI chief executive Sam Altman, and Google DeepMind co-founder Demis Hassabis made public statements of endorsement or qualified agreement.
The plaintiffs say they do not object to any single company slowing its own development. They argue that antitrust law forbids competitors from replacing independent decisions about product improvement with collective agreement, which they characterize as an unlawful restriction of output. The complaint pleads the claim as a per se unlawful restraint and, in the alternative, under quick-look and rule-of-reason analysis. It also seeks injunctive relief under Section 16 of the Clayton Act. The plaintiffs seek class certification, treble damages, and a declaration that the conduct violated federal antitrust law.
The plaintiffs also seek an injunction barring the defendants from coordinating on development pace, training compute, release timing, or capability checkpoints. The injunction would also bar the information exchange needed to monitor any such agreement. The plaintiffs have demanded a jury trial. On September 21, 2026, the court issued summonses to the four defendants. None has responded to the complaint or commented publicly, and no scheduling order, motion, or ruling appears on the public docket.
Timeline 4 events
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OrderCourt issues summonses to all four defendants
The summonses named Anthropic, OpenAI, SpaceXAI, and Google. None of the defendants had responded to the complaint as of the most recent reporting.
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FilingSubscribers file antitrust class action in Northern District of California
Four paying AI subscribers filed Buist et al. v. Anthropic PBC et al., alleging a Sherman Act Section 1 conspiracy to slow AI development.
OpenAI, Anthropic, Google, SpaceXAI Hit With Antitrust LawsuitAnthropic, OpenAI, Google and SpaceXAI face lawsuit claiming AI slowdown harms subscribers and violates antitrust laws
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OtherRival CEOs publicly endorse or respond to Amodei’s proposal
Elon Musk, Sam Altman, and Demis Hassabis reacted publicly to Amodei’s essay within hours. The complaint cites these statements as evidence of a coordinated agreement.
OpenAI, Anthropic, Google, SpaceXAI Hit With Antitrust LawsuitLawsuit says Anthropic, OpenAI, SpaceXAI, Google made illegal AI deal
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OtherAnthropic CEO publishes essay urging industry-wide AI deceleration
Dario Amodei published an essay calling for coordinated “pacing of the frontier” among AI labs on safety grounds, which the complaint identifies as the origin of the alleged agreement.
Lawsuit says Anthropic, OpenAI, SpaceXAI and Google made illegal deal on AI slowdownLawsuit Alleges Anthropic, OpenAI, SpaceXAI and Google Made Illegal Agreement for AI 'Pacing'
Experimental AI forecast
How it is made- Predicted outcome
- Insufficient evidence
- Model confidence
- Low
No forecast yet. The complaint was filed on September 18, 2026, and the only docket activity is the issuance of summonses. No defendant has appeared, moved, or responded, and no schedule exists. A forecast becomes possible once defendants file motions to dismiss or the court sets a briefing schedule.
No defendant response, motion, or scheduling order yet · Twombly plausibility of agreement based on public statements · Possible motions to compel arbitration under subscriber terms · Viability of per se theory for safety-framed coordination · Antitrust standing and injury for slower product improvement
Generated automatically by Claude Opus 5.5 on Sep 26, 2026 from this case’s record on this site, and published without editorial review. The probabilities are the model’s judgment, not measured frequencies, and they are scored publicly as cases resolve. Not legal or investment advice. How the forecasts are made
Disclosure: Anthropic, which makes the model that wrote this forecast, is a party to this case.