Pretty much what Waco said. The applying/white-listing procedure needs to be in place to prevent people from griefing. Unfortunately there have been many cases in the past where people decide that they would like to have a little bit of fun and destroy other peoples stuff. So in future, people need to apply and motivate why they wish to join. Once that has been done, they are added to the white-list and are able view/access the world apart from regions protecting spawn etc.
Generally the server is heavy on resources and requires a fair amount of maintenance, in terms of updates and player control. The amount of CPU and RAM usage is pretty phenomenal, even on a Xeon, haven't really seen that with any other game servers.
