Earlier quoted context omitted.
If a car follows your car, is that illegal? If a drone follows your car, is that illegal?
If someone systematically follows your car (drone or not), don't you think that should be illegal?
It might warrant a restraining order, sure.
Outside of judge's opinion that it constitutes stalking or threatening behavior, what exactly is the crime here?
Perhaps it's a neighbour who keeps the same hours and works in the same city block, etc.
Perhaps it's a PI hired to follow you because .. is that a crime?