In the long term, biometrics, by their very nature, will compromise privacy in a deep and thorough fashion. If and when face-recognition technology improves to the point where surreptitious cameras can routinely recognise individuals, privacy, as it has existed in the public sphere, will in effect be wiped out. No doubt there will be some benefits: fraud, in particular the persistent and increasingly annoying problem of identity theft, might be substantially reduced if biometric-identification systems, introduced in the form of passports, visas and identity cards, become widespread. But privacy advocates argue that such benefits are not worth the risk of “function creep” that once biometric passes have been issued by governments, it will be tempting to use them for all sorts of things, from buspasses to logging on to your office PC.