3rd party apps are not allowed to access the Social Graph beyond 1st level connections i.e. you cann't get friends of friends.
But I wonder , why does facebook not develop Apps based on their Social Graph by itself.
Could be it was because facebook wanted to focus and capture other important stuff like - facebook comment plugin , facebook like button, facebook share plugin ...
They always knew that replicating craiglist can be done any day later.
They always knew that replicating craiglist can be done any day later.