Do you count multiplayer games? In EVE I once baited some guy to, through game mechanics, allow me to kill his 200mil ISK ship. I then apologised and agreed to join his corp to stop him hireing mercenaries to decalre war on me (a threat often made, never done though, so no risk of him doing that). Then, in his corp with my friend, we waited till he was afk then locked down his 800mil isk + cargo ship, ransomed him for about 1.2billion when he got back, then killed him anyway.
To be fair, he did seem to be a bit of a dick, would've done it even if he wasn't, but he was.