Your 'response foreclosure' is confusing to me - I'm not sure on what grounds you decided that the FBI putting mandatory GPS on all cars was unconstitutional, but putting a GPS on any individual car might not be.

Maybe that was confusing, I'll say it a different way: your grounds for deciding that planting a GPS on an individual car was constitutional was that the effect could be duplicated by physically following that car. Is there some sort of physical limit that I'm missing to that argument? The FBI could physically follow around all non-FBI cars, and they would even run into economies of scale by just monitoring intersections and making paper records of every car that passed.

How exactly did you decide that tracking every car with GPS was not constitutional?