I'm envisioning some kind of pin or key that must be inserted in the transmitter before the power will come on to the RF portion of the radio. Obviously, the frequency of the transmitter must match the frequency of the pin/key pulled. Maybe it's like a two step system. The power switch allows you to program your radio but you cannot broadcast until the pin/key is inserted.

I've been thinking of this for some time but don't have the electrical knowledge to actually do it.