Well mine get checked at immigration every time.
Fingerprints are a simple way of verifying identity, as are iris checking and facial biometrics. For some reason we don't object hugely to the last two although we do seem to do so for the first, even though they all perform the same function.
UKBA are dropping iris checking and I'm convinced the biometric gates only let me through when the person on the desk hits the button, yet the US, who went for fingerprint recognition years ago has a system that works well. OTOH we have one that works less well. Of late I've been getting through faster in the US and suspect that's because the sytem recognises me.
Mind you there was
this, but I think I'd get spotted trying it!