I'm confused by it too, but I see it in some members of my family. Full grown, middle aged adults, absolutely ADDICTED to their Facebook feed. Sitting in a room full of people and glued to Facebook. I don't get it, but I can say without adult that those who are addicted to FB are also the most unhappy. So I see that correlation in my own life. I don't know that FB causes or contributes to their unhappiness, or if maybe it's an escape for them, but I see it.