Over 600 Google employees signed a letter to CEO Sundar Pichai demanding that Google block the Pentagon from using its AI models for classified purposes, reports the The Washington Post. Its organizers claim many of the signers work in Google’s DeepMind AI lab, and include more than 20 principals, directors, and vice presidents.

According to the Post, the letter says that “The only way to guarantee that Google does not become associated with such harms is to reject any classified workloads. Otherwise, such uses may occur without our knowledge or the power to stop them.” Anthropic is currently in a legal battle with the Pentagon over being designated a “supply chain risk,” after refusing to loosen guardrails around how the US military can use its AI models, with support from across the tech industry, including employees at Google.