An interesting concept, but surely then they would have access to the system we used to create them which would be as good as having them. In the end I think I'd not go paranoid over that particular problem, I'd think more about the nasty person who hacks your account for gain, and I'd like to suggest somee thing based on DNA, rather than anything else. Its no good using retina scanning as some people do not have eyes or at least ones that can be seen as normal, some people do not have fingerprints, I know two like that, no swirls, and I'm not keen on the Apple Face ID idea even though I'm forced to use it since its only max security if you have attention mode on and I cannot use that myself.
Maybe we should all be microchipped. I bet that would piss a lot of people off too. Some idiot would implant his in his pet or something. Brian