That grocery store cannot then tie it to not only who you are but who your friends are. They have your name and address, but they don't have your entire social

That grocery store cannot then tie it to not only who you are but who your friends are. They have your name and address, but they don't have your entire social graph at their fingertips. Or your entire digital (or, with the rfid, real-world) historical travel data. If this goes tits up, it could be just the kind of surveillance needed for a 21st century locked-down police state.