I definitely feel like we're missing positive opportunities for mass surveillance. Things like being able to recognize someone in cardiac arrest, or who is at risk for a stroke. Someday mass surveillance will help as much as it hurts society.
Could they? Oh well, that is at least something then.
Can those things actually be done with a vanishingly low false-positive rate? If I'm walking down the sidewalk and a camera sees me suddenly grimace because a rock got into my shoe, I don't want paramedics rushing to the scene to offer me assistance for a heart attack.