i dont know if there is one but i always wonder why i never found a plugin like when a player place his blocks that its directly protected or with worldedit when you place/spawn somthing with it that its automaticly protected i hope some who read's this can make it becouse it would take so much of my and other people's time protecting everything thanks schaambaart.
you may want to check http://dev.bukkit.org/server-mods/lwc/ and http://dev.bukkit.org/server-mods/grief-prevention/
