(If it can be used to troll or abuse players it will.) This is the 1st Law of the Wasteland. Law 2 of the Wasteland is (The proceeding excuse will be used henceforth for any opinion people do not agree with or that suggests limits to Law 1 and it is "The Wasteland is Harsh.") The laws have been written so they shall be done.
Really unless they're controlling 4 characters at once, it can't be stopped. And no matter how the system works, fast log or time out, refer to Law 1, they will find a way. At this point the only real way to avoid it is to avoid as much player interaction as you can, or suck up to a big gang and run around with a bunch of people. People will say how they don't have this problem, but there is some luck involved along with play times which can effect peoples interactions with others.