I'm sure the method was different, but way back in the day when I was playing Phantasy Star Online on the Sega Dreamcast, "digital mugging" was a common occurrence. The attacker would walk up the the victim, ask them to trade, and the victim's interface would lock up causing them to have to reboot the console. When they logged back in, all of their gear and money was gone. If the player hadn't been to the bank to make a deposit recently, they were screwed out of potentially hours of game-time work.

I never did learn how this was accomplished; it happened to me only once, after that I ignored any player I didn't know in real life, which cut out the MMO part of the game for me.