The act of sneakily masturbating onto a car door in such a way that the owner of said car will stick his hand in the mess before realizing it is there when he attempts entry into his vehicle.
The carjacker will typically attempt to do this in a time and place where he can watch the results of his escapades when the owner arrives, without the owner being aware he is being observed.
The act of repeatedly sending someone a Facebook friend request and immediately canceling it so that the other user receives a notification of the request but can no longer respond to it.