I don't want this to be taken as a blanket claim that there is no merit to considerations of privacy in this realm, but there is a critical distinction between flight tracking and license plate vehicle tracking. Am infinitesimally small proportion of people have to fly private planes without option. American society has become such that the same cannot so be definitively said about automobiles. For large segments of the population, their cars are, for better or worse, a necessity of their daily lives and opting out of their use would be tantamount to opting out of society as it is. Yes, people can move to places where cars aren't needed, either because other forms of transportation can fulfill they're requirements or because life becomes hyper localized and there's no need to travel the distances licensed vehicles are required for. But not everyone can do that, literally; hyper localized loves are typically underpinned by other people bringing crap to you in vehicles with license plates being tracked. For many people, getting between a job they need and a neighborhood they can afford to live in, requires a private car. Having those people movements tracked it's more of a concern to me than done rich person who decides to take their personal plane to Aspen for the weekend.