Christian's is the more important one, as he lets us know that your CD key is included (unencrypted!) in your config file. DOH! So make sure not to let anybody else get hold of your config, or you could find another player using your authentication key to play online, potentially preventing you from playing.
<rant>Unless I'm missing something, as soon as the authentication server goes down, nobody can play the game online. And if you can't get a connection to the server for any other reason, you can't play. And if somebody else gets hold of your authentication key, that stops you from playing as long as they are online. Does anyone else think this is a bad idea?</rant>