[vorpalhex]

Google absolutely allows you to confirm it's tags and uses that for retraining, which means yes, my facial profile is collected, stored and used for model training (unless you disable it in preferences).

You can't do "celebrity" recognition from a generalized data set.

[coleca]

Logically, that doesn't seem likely because that would mean any individual or set of individuals, could enter false data and poison Google's model going forward.