Why on earth is portals to the moon enabled?!? This needs to be disabled as soon as possible, its currently the most efficient and destructive greifing tool possible short of a nuclear arsenal, it ignores all rules, including the spawn protection. Ive had 2 personal safes sucked away with it, and everything else i own. (and I am yet to have any mod or admin settle the issue on the actually stolen ic2 generator, compressor, and iron furnace) This config option has made me have to start over, and has... for a lack of a more accurate word, raped the spawn and all the houses built by it. A side effect of greifing using this happens to be lag, because the block entities thrown by the portal gun dont go away for a long time.
Unless you want the entire continent spawn is part of to be stripped to bedrock I highly suggest you disable the portal gun's ability to place portals on the moon.