En route Key West to Fort Lauderdale, had comms failure and didn't fancy flying in Miami or Lauderdale airspace without radio (I have trouble understanding them even when the radio is working). Diverted to an airfield in North of the Keys (can't remember the name). Did textbook no-comms circuit join & land, only to be met on rollout by a security jeep with "commando" looking guys who escorted me off the runway. Before I had shutdown they were opening the door and interviewing/interrogating me. Seems it was a private airfield for the rich type and didn't like lil' ol Cessnas dropping in unannounced.
They escorted me to the tower and I called the flight club from whom I had rented the aircraft. Once I had fixed the known problem ( jiggled the wires as instructed) I was told to take off immediately and not to land back, even if comms are lost again once airborne.
This was all a long time pre-911. God only knows what those guys would be like now!!