A radical anti-AI activist who helped chain himself to OpenAI’s doors has vanished without a trace, leaving police warnings that he could be armed and dangerous.

From Protest Leader to Public Menace

Sam Kirchner built his reputation chaining himself to OpenAI’s San Francisco offices and staging hunger strikes outside AI companies. The StopAI co-founder transformed a simple “No AGI” social media campaign into a direct-action movement demanding humanity permanently abandon artificial superintelligence research. His theatrical stunts included serving a legal subpoena to OpenAI CEO Sam Altman during a live public event, generating headlines and arrests that kept his cause in the spotlight.

The movement’s civil disobedience tactics initially followed traditional activist playbooks. Multiple arrests during office blockades led to criminal trials that StopAI embraced as proof of their commitment. Kirchner and fellow activists like Guido Reichstadter portrayed themselves as willing martyrs facing jail time to save humanity from extinction. Their hunger strikes and door-chaining protests disrupted business operations while maintaining the moral high ground of nonviolent resistance.

Internal Fractures and Financial Disputes

Behind the public activism, StopAI faced internal tensions over strategy and money. Kirchner allegedly assaulted another member during a dispute over access to group funds, marking a dramatic shift from the organization’s nonviolent principles. The incident triggered fears within the activist circle about escalating behavior and Kirchner’s mental state. His social media statements began explicitly renouncing nonviolence, creating an irreparable rift with StopAI’s leadership.

The organization’s current interim leader, Matthew Hall, and other members made the extraordinary decision to publicly distance themselves from their co-founder. StopAI issued statements emphasizing their continued commitment to nonviolent tactics while making clear that violent rhetoric was incompatible with their mission. This public break transformed Kirchner from movement leader to isolated radical, setting the stage for his mysterious disappearance.

We got an answer: Indeed, StopAI’s Sam Kirchner did not appear at his court hearing the morning of his disappearance (and the OpenAI lockdown), and “a judge issued a bench warrant for his arrest.” https://t.co/JDTSYTpGmC pic.twitter.com/lcVbQD6IYR

— Nirit Weiss-Blatt, PhD (@DrTechlash) December 3, 2025

Threats, Lockdowns, and Vanishing Acts

OpenAI’s San Francisco office went into lockdown after receiving violent threats that authorities linked to Kirchner’s faction. The security scare forced the AI giant to temporarily disrupt operations and coordinate with law enforcement about potential armed threats against employees. This marked a dramatic escalation from civil disobedience to credible fears of workplace violence, justifying corporate security measures that activist groups typically condemn as overreach.

Kirchner’s disappearance roughly two weeks ago left more questions than answers. Police warnings describe him as potentially armed and dangerous, though the exact evidence behind these characterizations remains unclear. His whereabouts, intentions, and mental condition are unknown, leaving former allies, corporate targets, and law enforcement agencies operating in an information vacuum. The case represents every activist organization’s nightmare scenario: a founding member going rogue with potentially violent consequences.

Sources:

Futurism – OpenAI Lockdown Threat

KALW – Trial for Stop AI Activists Begins

Transformer News – A Brief Guide to Anti-AI Activist Groups

AI Topics – The Strange Disappearance of an Anti-AI Activist