Coupling un-alienable, (purposefully) unchangeable biological marks to any account is always horrible idea. And not just the privacy part, for one, it can (only) be unwillingly altered (eg. by an accident), the same way as fingerprints, so a secondary backup code is needed anyway, making the whole setup a bad sort of convenience feature. The proper solution would be a safe hardware key mechanism.
This is an important aspect. People are not aware how big the difference of this is to the usual account name and password. If you want to start over and register a new account, you can have that. Not with this technology. And with the amount of data which Amazon vacuums up, there are totally legitimate reasons for this. Let's say, just as an example, that your girlfriend has bipolar disorder and you order and read a…
It's a permanent mental illness and cannot be 'cured' or 'overcome'