Headline is, frankly, awful. This isn't the AI secretly doing stuff and hiding it. This is the very human Anthropic engineers trying to detect Chinese scraping via some frankly hamfisted and unimaginative URL trickery.
Here the system is "insecure" by design (literally they're trying to get the whole world to sign up for Claude Code for $200/month!) and they're trying to plug the hole that results from a "Except for Chinese Scrapers!" add-on requirement. That might be possible as an arms race kind of thing. But it's very unlikely to work by (as in the linked article) doing stuff like checking the system time zone.