One thing that I've noticed happening with facebook connect on boonex.us, is that your account name is always your first name from your facebook information. I don't know what will happen if another user with the same first name attempts to use facebook connect to sign up. Furthermore, it so seems that you are allowed to change your nickname. I tried changing my nickname from my real first name into my chosen nickname, and it let me change it without asking me to provide a password. So after logging see more out of my account, I couldn't log back in because my account didn't have any password set. So I tried to use facebook connect again to login to the site, which instead of logging me to my already created account, it went on to create a brand new account again.. using my first name.

Seeing that the facebook connect module doesn't have any more options than the api and secret keys, this could create serious problems with the user management and accounting. Any workaround there?