Humans being abysmal PIN and password generators, a decent fraction of phones can probably be unlocked within 5 attempts by just trying 123456, 123123, 111111,

Humans being abysmal PIN and password generators, a decent fraction of phones can probably be unlocked within 5 attempts by just trying 123456, 123123, 111111, 654321, 000000. Unless/until the phone forces the user to learn rather than select a PIN that's probably going to remain the biggest vuln.