I have a relative who is otherwise a upstanding and fine fellow, but when it comes to games likes to take "shortcuts." (In other words, he opens up the debug console and hacks himself all kinds of goodies) I recently started a "fresh" server with the idea that we'd all start off clean and gather/build together, and I caught him using stuff that we hadn't reached yet. This wasn't a case of him being a little bit ahead – we'd just beaten Eiktheir and he was suddenly wearing a suit of iron armor. He wasn't even apologetic about it.
Now, I actually enjoy spending time talking to my relative, and I know I'm not going to cure him of his "shortcuts", but I'd like to be able to enforce inventory "purity" on a server. Check the box, use the command line option, and instead of items being stored on the individual's computer, whenever the person logs onto that particular server, their inventory and food status from the prior session is restored. If they then log out and jump into another server that doesn't have that option enabled, they still have their character's original equipment left from before they entered the offline server.