Shoulder Surfing
The programme 'You and Yours' on Radio Four in the UK today focuses on a distressing tale of someone who meets someone else at a club and shares a taxi home, where his phone is eventually lifted. And because that someone else has seen the passcode in use during the taxi-ride, once elsewhere he logs himself in and circumvents Apple's much-vaunted Face ID by entering the settings and using his own face instead.
Subsequently he logs into much-vaunted online bank Monzo by means of Face ID, and empties it of a considerable sum.
Mentioned in the same feature the common practise of using notes or stickies to log all of those passcodes and passwords that none of us could be expected to recall... these are also available by the same nefarious means.
There is still an argument for protecting your ID using faces or objects that only you could be expected to know, but the question is not so much the 'in' to your phone as the 'in' to the potential market?
The programme though recommends looking over your shoulder every time you enter a passcode.
But who wants to live a life like that?