Anthropic Secretly Tracked Claude Code Users. Then Called It an “Experiment.”

There's a version of this story where Anthropic was trying to protect itself from large-scale model theft. There's another where one of the AI industry's biggest privacy advocates quietly crossed a line its own users never expected. What makes this headline important isn't just that hidden tracking code existed. It's that the company behind it was Anthropic. Just months ago, Anthropic publicly refused to let the Trump administration use Claude to surveil American users. The company defended that position in court, arguing that AI companies shouldn't become tools for government surveillance. That stance became part of Anthropic's identity. Then came a very different decision. In March, Anthropic quietly added hidden tracking markers to Claude Code that flagged users' timezones, proxy connections, and potential ties to Chinese AI labs. The code remained unnoticed until security researcher Thereallo discovered it last week. After the discovery went public, an Anthropic engineer confirmed it on X, described it as an "experiment" intended to combat account abuse and model distillation, and said the company had already planned to remove it. The tracker was taken down shortly afterward. The bigger question isn't whether Anthropic had a reason. It's whether a company that built its reputation on privacy can afford to hide surveillance from the very developers it asks to trust its tools.