Currently we have no way to moderate efficiently when someone is griefing and many items have been banned as a result. We are quite laid back as admins and incredibly lenient. You see kids will be kids and its hard to keep them from misbehaving, but also people keep finding new ways to raid. It really is Minecraft that's the problem here, there are just so many things that can bypass protections. I myself don't like the idea that you could lock up your base entirely and still be robbed because of the way Minecraft is coded.
I don't care for raiding at all, it just complicates things and means that we have to go to great lengths banning all the cool stuff and denying access to commands such as back and tpa to new members. If the server becomes a non-raid one then items such as the Quarry could be unbanned (but limited to the Nether, because we do not like eyesores). Moderating would be easier too, hanging around someone elses home would be considered grief and unacceptable. Using available items to destroy peoples property would be a bannable offence. With Grief Prevention it will be so easy for us to protect everything and Raiding would be impossible. Therefore the only thing you could do is grief.
We would have to setup events like spleef and create more warzones and content but that's a small price to pay for less grief. (People will be instantly banned for griefing if the server goes non-raid.)