Board Thread:Friend Code Exchange/@comment-26384327-20150514163752/@comment-24668482-20150515165937

This is only one of many forums/groups for the game, and although there is a small amount of cross over they each have their own user base. I guess you could look at player's friends lists and look for the rate of over lap to try and figure it out, but some players do keep on inactive friends as well as active ones.