Uh, right, but why would you run an authenticated v. non-authenticated server? Just to prevent pirates from connecting to your server because you support notch? Is it like Battlefield or those other games with ranked v. non-ranked where ranked offers persistent stats? I am curious if there is any benefit in running an authenticated server other than moral support for appearing on notch's list of approved players.
From what I understand the non-paid users have a much higher probability to be "griefers" or those that destroy buildings/piss off other users.
Because it offers a centralised way of nuking players off your server. And if they want to play again, a new copy of the game is 15 dollars more expensive than refreshing your IP address.