There are plenty of potential benefits, for example I flew home (to England) a couple of days ago and rather than queue for a while to have someone check my pas

There are plenty of potential benefits, for example I flew home (to England) a couple of days ago and rather than queue for a while to have someone check my passport I was able to pop my passport onto a scanner then have the machine check my eyes to see if I am who I claim to be, which meant that in 30 seconds I was out the other side. Facial recognition could speed that up even further. You could get home and your front door would automatically unlock as you approach it, get into your car with genuine keyless entry rather than just the kind that means the keys are in your pocket, pop into Starbucks and be handed your regular drink (or something you ordered on a phone) by somebody who has never served you before, etc. Don't get me wrong, there's plenty of arguments against this technology, and I'm not even saying that the good points will end up happening (there's plenty of technological improvements Starbucks could make with existing fairly basic technology already), just that it isn't hard to imagine more than just Facebook-style photo tagging.