An artificial intelligence researcher has resigned from Anthropic PBC and called on other staffers to rethink their work, citing his concern that the company and its top competitor OpenAI are acting irresponsibly in their all-out pursuit of a technology that poses existential risks to humanity.

US security agencies accused China’s top AI companies including DeepSeek and Kimi maker Moonshot AI of systematically extracting proprietary knowledge from American firms and warned Silicon Valley developers to protect their work.