...which, as anyone has tried to use the "service" will attest, is perhaps the worst possible example of identity verification you could use, from a user's perspective.

I know it's amazing to some, but a good amount of people have no clue the exact amount they paid on their last visa bill.

The US postal service's mechanism for doing this is slightly less invasive; they charge a $1 fee to your credit card card so they can confirm that the card's billing address is one of either the "old" or "new" addresses.