http://www.ecocitycraft.com/forum/threads/behind-the-portal-area-fixed-the-grief.17324/ This was from a while back. At the time, the mining world was far worse than it was in the screenshots in this thread...like, it wasn't just a wall, it was a giant 100x100x100 solid block of sand, a hole to bedrock every few spaces, more cobblestone in the sky than you can try to count the pillars of...it wasn't even a warzone, it was nature gone wrong. Enough bragging from me though - nice job!
It IS un-griefable, but only to an extent. You can't destroy or place blocks. However these few individuals realized how to do it using water+lava to create blocks in an area you should not be able to. Truly this is abuse of a donor feature, but we hate to take things away people paid for. Those involved served a ban and have been warned. If it seems to continue then we may need a harsher punishment. RagMan
You know that PvP arena in the mining world about 3 mining worlds ago? I turned it into an ocean and drove around in it and fished good times... until I get murdered and it got cleaned up