writes "Cryptography is pretty much useless against this a problem referred to as “friendly fraud.” It’s not because the typical family member can crack PINs and passwords. It’s because many people tend to occasionally share or reuse passwords, or leave their devices unlocked at home. Here is something odd about stealing: People feel worse about stealing cash than they feel about stealing abstract representations of cash...
We ran a survey with over six hundred subjects, grouped into four groups. In one group, we measured the willingness to commit fraud where a “normal” checkout was used. In a second group, we added the guilt (face + hand + bill) component. In a third, we added the detection (photo) feature to the normal checkout. Finally, in a fourth group, we added both the guilt and the detection aspects...."Link to Original Source