This is simply not possible. When somebody connects to your server, it gives them all the information about the bricks you have placed so they can see and collide with them correctly. When they decide they want to save the bricks, they take the data you have already given them and convert it into a file. You don't even need to tell the server you have saved the bricks. However, if they want to save events, they do have to request those from the server, so, theoretically, you could tell your server to not provide them with that information, however, Badspot would not allow it for the reasons Gen. Nick posted above. If he caught people doing this, he would simply make the function off limits to everyone, so nobody could stop it.