Weird, I see the following if I’m not logged into codecombat:
and the following if I am logged into codecombat:
So I’d guess that is just a “use facebook/google+ to find your facebook/google+ friends who are also on codecombat.”
If you are logged into CodeCombat you can “fight” anyone on the list, and spectate any battles you want . . . and there is a more button to see “more” of the list if the people you want don’t show.
(sometimes I have to reload the page a time or two to get the more button to work…)