I just started using an iPhone with touch id. You know, that's absolutely not safeproof against thieves. If someone wants to steal your data or have access to your stuff on your iphone, the 'attacker' has to knock you out. While you're unconscious, all they have to do to open up your iphone and access all you credit cards and anything else on your iphone is to take your thumb, put it on the device and everything will be revealed. Or your girllfriend just has to wait until you're deep asleep with your arm out of the bed, take your iphone, take your thumb gently and VOILA! With a 4 digit password, you just can't do that. I thought it was a great option, but not really when you think of it.