#telemetry

Anthropic's Claude Code version 2.1.91 includes obfuscated code that checks for Chinese timezones and proxy URLs, then encodes region information into prompts sent to the API without disclosure in changelogs. This raises serious concerns about user privacy and transparency in AI tools, as it could be used to identify unauthorized usage or model distillation without user consent, potentially undermining trust. The detection logic uses XOR obfuscation with key 91 to check for timezones Asia/Shanghai or Asia/Urumqi, and proxy URLs pointing to Chinese domains or AI labs; region data is encoded by altering the system prompt's date format and Unicode apostrophe.