Hah! from the point of view of the user, this is already possible even with password-based sites. Instead of logging-in with your previous password (which of c

Hah! from the point of view of the user, this is already possible even with password-based sites. Instead of logging-in with your previous password (which of course you forgot), you just claim that you lost it and request a recovery email each and every time. I do this almost systematically and I'm happy with that.