For a while, a good friend of mine would terrify me by taking the wallets off of strangers and then handing it back to them. He told them that it fell out of their pocket and he never took anything. I don't know if he did it for a personal thrill or to get a rise out of me but I have to admit it was entertaining. It was mostly from behind while we stood in line or walked in a crowd so he didn't play any of the psychological tricks mentioned in the article. He was just opportunistic and thought it was funny when I yelled at him later.