Ya gotta love how Anthropic said one thing and did the other lol. I am not surprised that they were trying to track users in China (remember Anthropic said Claude Code wasn't in China), given the illicit distillation that China has been executing. Illicit distillation is where developers use automated networks of thousands of fake accounts to bombard Claude with millions of specific prompts, essentially harvesting the model's advanced outputs to train their own rival AI systems at a fraction of the cost. It is a key strategy to catch up to the U.S. models.

Anthropic quickly removed a tracker secretly monitoring Claude Code users in China after a security researcher exposed the hidden code and condemned the spyware-like tracking as a “serious breach of user trust.”

I have to say, though, that given how clear it was and how easy it was to find, I have a hunch that there is a much deeper and more elaborate tracker embedded deep into the model to allow Anthropic to continue this search. I'm chalking this one up to a quick and easy catch so that people could catch it, they would get rid of it, and people wouldn't worry about it anymore.