Not hard. I've done it. Basically having the words "Can", "Have", and "Admin" in that order banned the user for 30 Minutes. I'll see if I can find the script.
Oh, and there IS a way to get a save loaded without asking for admin. Post it online, then have them check it out. It's only worked for me once. Most people won't go that far out of the way. He liked the save anyways. It was Reactor's Hangar.