In 1.0 you guys should ask for real life ID or something before a game account becomes activated. It would be much harder that way for banned players to return that way. If you got the real life name of a player and the country/state/city where they live from that ID and the rest of info blacked out. It should be enough to identify and make security harder.
LOL DNA is the only way and even that's wrong more often than you want.
We're not a government agency, no way to validate fake credentials and it just makes it hard on the good people who just want to play.