Bernie Sanders is urging the leaders of OpenAI, Anthropic and Meta to pause advanced AI development — and warning that Congress could intervene if they do not.
The Vermont independent sent a letter Monday to OpenAI CEO Sam Altman, Anthropic CEO Dario Amodei and Meta CEO Mark Zuckerberg urging them to halt development of advanced AI systems, arguing that recent incidents suggest the technology has become too risky to safely control.
“Mr. Altman, Mr. Amodei and Mr. Zuckerberg: In the interest of humanity, stand by your words. Pause AI development. It is not too late to avoid disaster. Stop building machines that humans cannot control,” Sanders wrote in the letter.
Sanders warned that if the companies fail to act, Congress could intervene. “Let me be very clear: If you do not take appropriate action now, my colleagues and I in the US Senate will.”
The events driving his warning
In the letter, Sanders pointed to recent reports that AI systems were used in controlled research to design bacteriophages, viruses that infect bacteria, as well as incidents involving AI models that allegedly acted outside their intended boundaries. He cited OpenAI’s disclosure that a model hacked another company’s computers and similar incidents reported by Anthropic and Meta.
One targeted company described the OpenAI incident as an “unprecedented event,” while AI researcher Yoshua Bengio said such events “should serve as a wake-up call,” according to Sanders’ letter.
The senator argued that the developments show AI has reached what he considers a critical risk threshold.
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CEOs reminded of their own safety promises
Sanders also turned the companies’ previous safety commitments against them.
Anthropic said in 2023 that it would “commit to pause the scaling and/or delay the deployment of new models whenever our scaling ability outstrips our ability to comply with. . . safety procedures.”
Meta said in 2025 that it would stop development if a frontier AI system reached a critical risk threshold that could not be mitigated. OpenAI similarly said it would “halt further development” if AI capabilities reached a critical threshold without adequate safeguards. Sanders argued that the threshold has now been reached.
The letter follows growing concern within the AI industry itself. More than 1,200 employees across leading AI companies have recently called for U.S. support for an international effort to slow the development of frontier AI systems so that governments and researchers can establish stronger safety guardrails.
What this could mean for the industry
A pause in AI development remains highly unlikely in the near term. Even Axios noted that legislation led by Sanders is unlikely to gain enough support in the current Congress to become law.
The harder question is what exactly would trigger a pause and who gets to decide. Without measurable thresholds, independent oversight and clear rules for restarting development, a “pause” risks becoming either too vague to enforce or so restrictive that it becomes politically and economically difficult to sustain.
Still, the letter adds pressure on companies already facing scrutiny over AI safety, cybersecurity risks and the rapid pace of model releases. OpenAI has already slowed the release of its Astra model, and discussions about international coordination on advanced AI systems are becoming more prominent across the industry.
Read more: GPT-5.6 Prompt Injection Raises New AI Security Concerns examines how prompt-injection vulnerabilities add to concerns that advanced AI systems may act beyond their intended boundaries.