At first, I thought it was a great idea that other people could upload photos of me and tag them so everyone else could see. For some users, especially girls, this feature makes them feel like mini celebrities surrounded by digital paparazzi. “Hey, that girl I hooked up with years ago is now at the beach with some guy,” I’d think. “That other one’s milking a cow on a farm.” Funny stuff—until I started wondering why I’d want people I haven’t seen in ages checking in on what I’m doing now.