Someone I know just had their Google account compromised, but the normal recovery methods don't work for an interesting reason: the attacker has made the account into a "child" account subordinate to an attacker-controlled "parent" account. This apparently blocks the ability to use any of the Google account recovery methods (backup phone number or email address etc) without parental consent.

Apparently this person I know isn't alone, if you search you can find other people reporting they've been victims of this. And of course, Google support is nonexistent for ordinary users, so there's no real recourse. Let this be a warning about the consequences of ill-thought-out "child safety features"?