[java-man]

the big difference is that the data is stored temporarily in a human brain.

as opposed to, you know, somewhere in a poorly designed system which gets hacked.

(sorry, apparently joined a chorus)

[seanf]

The photo on the card is already stored in a system somewhere, and already vulnerable to attack. The brain is just for authentication at the door.

[java-man]

good point, though there might be a bit more biometric data required for a good facial recognition system.

[John_KZ]

Not necessarily.