Some good counterpoints. But you're suggesting more people would be okay with 'PI following them' hypothetical than GP suggests—simply with the knowledge that others are subject to the same degree of surveillance?

I'm not so sure that counterpoint in particular holds. I think to say the "number of people that are going to be okay with that will [still] plummet" is an understatement. I'd go so far as to say no one, at least no rational person, would be okay with a "record [of] who you talk to, when, how long, where you go, what you do, what you say, when you sleep", etc., just because of the scale.