> A combination of MAC and IP address ban should be sufficent.

Banning based on mac address could mean banning a whole subnet, if that network happens to have an application level gateway (firewall). Banning based on ip address is unusable, since most users have dynamic addresses. (dialup and cable systems are usually configured for dhcp) Banning based on a dns address is also unusable, since many providers associate the dns name with the dynamic ip address. (like line-123.provider.net, 123-123-123.provider.net) If the user just disconnects and redials or restarts it's cable/dsl modem, then the dhcp server will give him a new address, and some unlucky guy will get the banned address.

Imho the only usable ban is the per account one, which is fully in the server's control.

Viktor

As someone kindly mentioned, the best route would be to charge. Even if you were offering a free RPG, im sure most people wouldent mind a $1 startup charge (no montly). Wont really make you any money, but it will cut many of the 9-13 year olds that are oft the ones banned. Have them explain to mommy they need a new user again, when they read its a one time fee.