Was playing on the Nomadcraft server and my faction allied with another that had VIPs (read: Donators) in it. They proceeded to use the alliance chat to track down our base in full enchanted diamond EVERYTHING, and stay next to the one bed the faction owned, killing us as we spawned. This lasted for quite some time, until we ran out of faction power and they torched the place (it was an arial jungle village in the making, with several hours constant work gone into it). After we moved and let a newbie into the faction to bolster our numbers and faction power, they accepted a teleport request for the head of the enemy faction RIGHT IN THE MIDDLE OF OUR UNFINISHED BASE. We didn't even have anything to take, it was just griefing at that point.