Black vans
"If suitable precautions aren't taken, a team of knob-turners in a van parked on the jetty - or a "fishing boat" lurking nearby at sea - could conceivably tune into much of what was happening in a cutter's ops room or signals office, lifting the info unencrypted from the ship's internal systems."
This is the stuff of fiction. The CIA don't need to do that to know where the cutters are going to be, so their drug running pals dont trip over them.