Excellent concerns and questions Archonious. I'm curious to know DU's response on this as well. While I prefer that DU maintain their current position of "you will be able to dig (destroy) the ground", I have no experience in the MMO's you mentioned and am unaware of how much of an abuse it turns into in those games. In my opinion it would be good to have SOME way to defend against tunnels. Else there would be little point in a large city having a heavily defended border wall.