The under 13 thing, as has been discussed before, is due to COPPA. Google doesn't offer anything like hotmail's family account (where the child's account is managed by a proven parent's account), so if they find out that you're under 13, they
have to close your account and they aren't allowed to warn you that they will do so (or let you go back and change your birthdate).
As for the pseudonym thing, that never occurred. People lost their google+ accounts, but the rest was just forum posts saying things like, "I remember reading about someone..." without providing the actual citation.
