Planespotters to be freed on bail: “Fourteen tourists on a Greek aircraft-spotting holiday may have spent six weeks in prison thanks, in part, to a quirk of mathematics. Planespotters, like trainspotters, are obsessed with collecting the numbers of the vehicles that they see – and unfortunately this habit is indistinguishable from one form of hostile intelligence-gathering…

The Greek authorities have expressed concern over records of serial numbers from the tailplanes of helicopters at the base. A handful of such numbers can reveal a surprising amount of information about total number of pieces of equipment and even production capacity.” New Scientist