Tell this guy who got in your machine through ICQ he's a dumbass if he doesn't know how he could get kicked. One way to eliminate all connections to your machine is to have zonealarm and hit the big "STOP" button. That cuts all connections and if the program isn't set to bypass the lock, it'll shutdown. This is the first thing I could think of for an immediate workaround, although there are other ways for it too.
