Actually, they should check for homing pigeons.
MIAMI | A retired State Department officer and his wife who are accused of spying for Cuba appear to have avoided capture for 30 years because their communications with the Caribbean island were too low-tech to be detected by sophisticated U.S. monitors.
U.S. intelligence spends little time combing the shortwave bands for secret, nefarious transmissions, said James Lewis, director and senior fellow for the Technology and Public Policy Program at the Center for Strategic and International Studies in Washington.
"I'm not surprised [the U.S. intelligence community] missed this," Mr. Lewis said. "We don't put an emphasis on monitoring this kind of activity."
Which is one reason why the Cubans use this technique. The other reason, of course, is because their ruling regime is shackled to a inferior and discredited economic/political philosophy whose only successes have been in turning large numbers of live peasants into dead ones.
At any rate, check the pigeon fanciers in southern Florida. Just in case.
Crossposted to Moe Lane.