Inactives building
I'm not sure if the inactive accounts ever get cleared up, but on Server21 we have a LOT now....they all have 0 army and little to no resource. So if they are going to stay, lets make them useful, whereby you can gain a little prestige by attacking them everynow and then.
This probably won't benefit top ranked players, as the little prestige prob wont be worth it, but it would encourage newer players to stay active, as they'd actually have viable targets from day 1!