If you have a new US passport, you take information about your iris, earlobe, structure of your face, or the size of your eye sockets with you every time you cross a border. The new passports store biometric data on a chip, which can be used to authenticate identity.
NPR reports that officials believe the new documents mark a major advance for border security, especially as more countries adopt the "ePassports." So far about 70 countries issue them. Unfortunately, the current technology isn't perfect. Face recognition might miss a fake or accuse an innocent.
How do you feel about biometric passports?