John Lettice writes for The Register on the difficulties associated with relying on biometrics.

It will all be very costly, he says, and the pseudo-certainty that it supplies may actually cause mistakes to be made, when the ID checks out but the surrounding facts look dodgy.

If you do not check for duplicates, for example, then the system is not going to tell you that Fred Bloggs of Sollihul is in fact Osama bin Laden. A silly example? Yes and no – obviously, it is not very likely that our current entry systems are going to let someone called Fred Bloggs walk through when they look strangely like Osama bin Laden. However, if he checks out as Fred Bloggs, UK citizen, with no record under our future automated systems, then general appearance is rather less likely to be challenged, or even noticed. So the assumed reliability of the systems could actually increase the security of fugitives in the event of their having successfully obtained clean, genuine ID.

There is much more.