1. having given up on finding anything interesting on Facebook, Facebook Idling involves sitting in front of the Facebook Newsfeed, just waiting for another update that you know won't be any more interesting than the last
2. as opposed to Facebook Stalking, a much more far-reaching and comprehensive way of wasting your entire life
Person A: "You must be Facebook Stalking hard right now man; you're not even clicking the mouse!"
Person B: "Actually, I'm Facebook Idling. I need to know what all my acquaintances are doing rather than just investigating one."
Person A: "Dude, are you Facebook Stalking that girl again?"
Person B: "Nah, I've got enough info on her. Now I'm just Facebook Idling, waiting for her to post something."