In United States v. Jones, the government’s argument mostly centers around that there is no reasonably expected privacy when one’s driving on public roads. According to the government, there is nothing a GPS tracking device can do that a surveilence team can’t, so if government doesn’t need a warrant to tail somebody, nor would it need one to install a GPS tracking device on someone’s car.
Let’s forget for a moment hair-splitting arguments like “humans go to sleep but robots won’t!” It would seem to me that there is a small yet logically clear-cut hole in that line of reasoning. It is based on the assumption that as long as the person being monitored is driving, they are driving on public roads, which is obviously not necessarily true. What if they were to decide to get on a private race track and have some fun? What if they were to be invited to some private party where the estate compound is entirely not visible to anyone observing from any public area? Under such circumstances, it would certainly be reasonale to expect some privacy.
Some might argue that those are just corner cases and most of the time when we drive we do drive on public roads. Of course they are, and we do, but that doesn’t mean that they are ignorable. While the idea and scope of constitutionally protected rights are broad, what really needs protection is precisely the “corner cases.” For instance, of all kinds of speeches, the one kind that really could use constitutional protection, the political and controversial kind, only takes up some tiny percentage of all the speeches people ever make, yet we don’t dismiss those as corner cases.