What were to happen if you took a picture of the owner's face and put it in front of the camera for the unlock?
If you always seem to have drama in your life, you are probably the one causing the drama.
If customer service representatives or restaurant servers always seem to be rude to you, you are probably the one being rude.
If your computer always seems to be freezing up on you, you're probably doing something wrong.
In my experience, drama begets drama, rudeness begets rudeness, and ineptitude begets ineptitude.
We actually had a similar discussion in one of the news threads about this. It was concurred that the "advanced" recognition technology would [we assume] be able to make the distinction.
An interesting point was brought up, by I believe Trusstopher. Something that would be cool about it is if someone has tried to access your device and failed it would show you a snap shot of that person. Obviously speculation but I would imagine it could have the capability to do so, if not now, at some point.
That's the same issue that laptops that use facial recognition unlock deal with. They handle it many different ways. First off, if you hold the picture at any kind of angle it won't work because the measurements of your face won't match up. In other words if the picture is tilted it will either make your features look longer or fatter. Secondly if the pic doesn't match ambient lighting then it is discarded. Any shine on the pic would also throw it off.
But that's all things that computers with face recognition do, I have no idea if the cell phone will do it. If you need ultra security for national secrets then don't use it. If you want to keep people from finding the nudie pics of your girlfriend, then facial recognition should do the truck.