[Tangurena]

Existing iris scanners can be deceived by pictures of other people's irises. I do not doubt that facial recognition will be fooled by people making masks (to fool infrared scanning).

http://www.schneier.com/blog/archives/2012/07/fake_irises_fo...

http://www.bbc.com/news/technology-18997580

The basic principle of biometric reading is the equivalent to sliding your photo under the door to a guard. The guard checks the photo against an already existing set of photos and lets you in. They don't check that the photo is of you - which is a common failing when you let marketing design your security.

[lifeisstillgood]

This is because everyone thinks a biometric is some sort of password. It is actually a username. You are stating I am the person whom my fingerprints/face/retinas state I am. Then the guard should challenge that person with that face to provide a password that is known to be held by that face.

Its a common fallacy that leads to people having their fingers chopped off to steal their fingerprint-recognising cars.