What if there was a 1-3 day waiting period for new accounts? Restricting new accounts by implement a invite system is option, but not good idea. Maybe a limit for new accounts from the same IP (if that is even possible).
Satan said:
"You are for ever angry, all you care about is intelligence, but I repeat again that I would give away all this superstellar life, all the ranks and honours, simply to be transformed into the soul of a merchant's wife weighing eighteen stone and set candles at God's shrine."