Just like there is a federal law that says you have a write to receive over the air communications, yet there are some states that stop you from driving while r

Just like there is a federal law that says you have a write to receive over the air communications, yet there are some states that stop you from driving while receiving those radio communications (i.e., they make radar detectors illegal in the car). The prohibition isn't on using a radar detector (you can walk around all you want with one), but against driving with one.