I have only just become aware of this as a player I had banned for unimportant reasons had actually managed to come back for revenge on another account and stole my world (like copied it and put on his own server) as i said I have only just become aware of this, how can I prevent this from happening? is there a way? I am quite frustrated that someone can steal over a years worth of work on a spawn town and just use it themselves...
From my understanding these are basically mods or programs that take the incoming chunk data and saves it. So no you can not stop it short of not sending the chunk data (but that would make them not see the world so their is no point to that).
With the mod that you copy the map there is no way you can stop it unless you stop sending chunk data to the player which in that case means not loading the map for them. Therefore there is no way of preventing this, just make your server the best and players will pick yours over his.
There's no way for you to prevent this at all. In order for players to actually play on your server, chunk information needs to be sent to them, there are mods out there that will log this into a new map.
I would expect Orebfuscator would cause quite a bit of issues for these people. Not its intended purpose, but probably effective. I say probably, but I couldn't say for sure.