Two members of the Lothian and Borders traffic police were out on the Berwickshire moors with a radar gun recently, happily engaged in apprehending speeding motorists, when their equipment suddenly locked-up completely with an unexpected reading of well over 300 mph. The mystery was explained seconds later as a low flying Harrier hurtled over their heads. The 'boys in blue,' upset at the damage to their radar gun, put in a complaint to the RAF, but were somewhat chastened when the RAF pointed out that the damage might well have been more severe. The Harrier's target acquisition computer had locked on to the 'enemy' radar and triggered an automatic retaliatory air-to-surface missile attack. Luckily(?), the Harrier was operating unarmed.