that is an interesting idea. still… you can create an account (or have a troll farm of such accounts) that will mainly be used to trust bots and when their reputation goes down you throw them away and create new ones. same as you would do with traditional troll accounts… you made it one step more complicated but since the cost of creating bot accounts is essentially zero it doesn’t help much.
it could and did happen. I remember reading about 6 year old kid getting lost at the airport gate (i think it was in germany) only to be discovered when they finally looked for their parents in italy. just went away while parents were preoccupied with something else and looked like someone else’s kid while boarding the plane. as a parent travelling with small kid I can totally see that happening anywhere - kids can just walk anywhere with no questions asked as long as they are next to an adult who looks like they could be their parent.