If it was actually used in a useful way (allowing you to friend a player, and possibly send them messages), then that leaderboard would be much more useful as a sort of friends list and I'd love to keep it. Right now all it does is track people you're connected to on facebook, which not only slows the game down and eats up battery/data with its requests to facebook for user/friend data, but it is completely useless for chinese players where facebook is blocked. Even if you disconnect from facebook, the app still seems to make requests to it on startup. In its current state its not useful, and actually detrimental to users on metered connections.
A year+ later and it's back!!! Thank you midoki for dropping the dead beats at rovio and listening to your customers... It's appreciated....