See Who ‘Unfriended’ You on Facebook
Want to see which of your clients or colleagues may have “unfriended” you on Facebook? A third-party script program — not endorsed by Facebook — called Unfriend Finder notifies you whenever a “friend” decides to part ways with you. Your message will come to you in the same way as a friend request or message.
You may need to revisit your wall posts if you find you’re being “unfriended” in the masses, or the “unfriends” may even cue you into viruses that lurk, which may mean you need to start taking action to protect your account.
Facebook has largely fought against such “unfriend” finding features as this and does not endorse or plan to implement its own “unfriend” application.
Facebook wants “users to feel free from discouragement or negativity when posting or experiencing their platform,” a recent article about the “unfriend” feature at Forbes.com notes.