If Anthropic decided to just send the user timezone as plain text instead of doing this obfuscated way, like "Today's date is 2026-06-30, timezone is Asia/Shanghai", how many of us will catch and question this behavior? It looks perfectly normal, right?

The question is about accountability. Right now these big closed-source model companies can do whatever with the data, and no one can hold them accountable for unacceptable data handling decisions.