>Why does the "confirm password" field exist anyway? It exists to remove the risk of input error. They want to avoid you locking into a mistyped password and not being able to recover.

It seems silly to force everybody to doubly enter their password, when I'd guess at most ~10% of people might enter an incorrect password on their first try at which point those unfortunate ones are only a few minutes away from a password reset... where they would be sure to get the password right that second time.