Anthropic researcher Jacob Coxon resigns over AI extinction fears, denies coordinating with outside groups

A researcher who spent four months at Anthropic before quitting in protest has become one of the most-discussed figures in AI safety circles, and he wants to be clear about one thing: he did it alone. Jacob Coxon, a 27-year-old British AI researcher, resigned from Anthropic on September 8, 2026, publicly warning that the industry’s race toward self-improving superintelligent AI poses catastrophic risks. Ahead of his departure, he consulted counsel from a nonprofit and briefed a journalist, but he denies that any third party coordinated or orchestrated his resignation. Why a four-month tenure made this much noise Coxon’s warnings spread fast. His post on X describing his reasons for leaving drew over 100 million views, an unusual level of traction for an essay-length thread about AI alignment written by someone most people had never heard of. Coxon joined Anthropic in May 2026 after previously working at OpenAI from 2023 through early 2026, where he contributed to GPT-4o. The recruitment process was lengthy, which makes his exit timeline striking: he left without waiting for the standard six-month equity vesting threshold, effectively walking away from meaningful compensation to mak...