The solution is that there is no preemptive solution, any more than there is a preemptive solution to using an axe dangerously. You can build a transmitter out

The solution is that there is no preemptive solution, any more than there is a preemptive solution to using an axe dangerously. You can build a transmitter out of a Raspberry Pi and a short length of wire; for extra credit, you can buy a cheap amplifier and really go to town, but the simple fact you can strobe a GPIO pin fast enough to transmit on unauthorized frequencies is the final nail in the coffin for any plan to restrict broadcasting by restricting radio sales. The enforcement comes down to this: If you transmit in an obnoxious way and you annoy someone, you get squashed. If you kill someone, you get squashed harder. That doesn't bring the dead back to life, but sending someone to prison for killing someone else with an axe doesn't bring the dead back to life, either.