Also, it is probably possible to narrow down pin codes by looking at the surface of the phone for finger prints/screen damage. At least on Android, the unlock

Also, it is probably possible to narrow down pin codes by looking at the surface of the phone for finger prints/screen damage. At least on Android, the unlock will appear in the same location every time and unless your pin uses every digit, there will be heavier use in some areas. It is unfortunate that stock android does not rotate the input keypad, I believe some ROMS (AICP?) would do this and thus eliminate this attack surface.