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-seeker had locked on to the `enemy' radar and triggered an automatic retaliatory air-to-surface missile attack. Luckily(?), the Harrier was operating unarmed.