Re: storage of data for mined data questions, you make a good point, and are most likely correct, though obviously it could be exploited. Just having the ability to mine the data like they do, opens it up for abuse, unless they are precluded from ever seeing the answers (which is possible, I just don't know if they actually do that).

Biometrics isn't 100% effective, but we're not talking about everyday casual use here, only occasional use, and we're not talking about a system without a backup (all of these companies will do a reset manually over the phone if you can't do it online). And many companies already restrict where you can reset your account info from (for example, from your home phone number only).

The ultimate point is not that biometrics is perfect, only that it's less imperfect than shared secret questions which are either too easy to figure out, or too difficult to remember.