But where their sociality had truly exploded was in their “weak ties” — loose acquaintances, people they knew less well. It might be someone they met at a conference, or someone from high school who recently “friended” them on Facebook, or somebody from last year’s holiday party. In their pre-Internet lives, these sorts of acquaintances would have quickly faded from their attention. But when one of these far-flung people suddenly posts a personal note to your feed, it is essentially a reminder that they exist.