This other server that I play on uses this and greatly reduced greif and obnoxious players.
What they did was that you had to register with the forums to gain full access with the server. The new players could still build and such. But couldn't acsess the iconomy, sethome, or use warps. I was thinking since we are getting so many new players that just wanted to make our life's miserable, we could use this. It would bring in more or only legit players and we wouldn't have to be so stingy on who we let into our factions.
What unregistered players couldn't do:
Sethome, use warps, use the faction commands, and iconomy.