Slight correction - it has access to your friends who have also used the facebook login for that site.
If you're the first person to login, the site will get an empty list. Only the set of your friends who have previously used the service, will show up if the service queries fb for your friends.
If you're the first person to login, the site will get an empty list. Only the set of your friends who have previously used the service, will show up if the service queries fb for your friends.