Oh yes. Also, cell phone conversations, the radio trunk lines used by private dispatchers (taxi cabs, delivery and construction trucking firms), public utility

Oh yes. Also, cell phone conversations, the radio trunk lines used by private dispatchers (taxi cabs, delivery and construction trucking firms), public utility fleets, you name it. Even into the late 90s you could buy a cheap Radio Shack scanner, dyke-out some diodes (put there to lock out certain frequency ranges, per some FCC rules) on the motherboard and listen in to all kinds of things.