Researcher quits Anthropic with warning over existential AI

Safety researcher Jacob Coxon resigned from artificial intelligence developer Anthropic on September 9, 2026, leaving an internal message on Slack in which he warned that the rapid pursuit of superintelligent systems without adequate caution and industry cooperation created “a risk of causing human extinction.” He posted the message internally.

The departure notices inside Anthropic concluded around 8:57 PM EDT following an initial report recorded at 2:18 PM EDT as Coxon finalized his exit from the company.

I resigned from Anthropic today. I spent the last three years doing pretraining research at both OpenAI and Anthropic. Neither company is acting responsibly. They are racing straight to self-improving superintelligence and gambling with our lives. More thoughts below.

— Jacob Coxon (@hilbertspaess) September 9, 2026