Fonline is not, and for legal reasons cannot be, a pay-to-play MMO.
While good in many ways it means that there is no way to restrict number of accounts per player. This leads to some serious problems:
1) Endless specialized alts for every purpose.
2) No meaningful way to sanction or remove problem players. Griefers, exploiters, trolls, and outright cheaters can act with impunity to spoil the game for legitimate players because even if they get caught and banned they can just make another account and be back in business.
#2 in particular drives people away and seriously jeopardizes the long-term future of the game.
My proposed solution is to require a modest, say 10USD, deposit to register an account. This could be sent by paypal and would be refundable, with the resultant closure of the account, at any time while the account remains in good standing. If an account is suspended then the deposit will be frozen for the duration of the suspension. A banned account has it's deposit forfeited as a donation to the keep-the server-running fund. The TOS agreement signed as part of creating an account would authorize such measures.
This would restrict the number of alts running around and drastically improve the play quality of the game without violating the not-for-profit nature that enables it to exist. No money is being made, even the forfeiture for being banned is donation, agreed upon in advance.