If you set up a broadcast station, you deserve to be df'ed and mugged. Any real plan that went as far as considering encryption, should also include coordination of limited time on air, multiple frequency and/or band usage, mobile or at least movable transmitting to avoid df attempts. I've been following some threads on other forums on the same lines of thought and learned a little about fast acting single point df equipment. To say its expensive and exotic is understatement.