Last month, it was reported that facial recognition will be used to take attendance in Singapore's Parliament and check into certain hotels. The latest phones already unlock with Face ID and many buildings - including University Hall at the National University of Singapore - use face scans to control entry.

This use of biometrics for security - relying on the uniqueness of your face, fingerprint or iris - offers the prospect of a world without passwords to remember or identity cards to show. Facial recognition in particular is fast, contactless and able to identify multiple people at the same time. These benefits could smooth movement through passport control or keep a vigilant eye out for known criminals. Yet those same qualities could also enable mass surveillance on an unprecedented scale.