As reported by the French magazine Moto-Journal: In the western suburb region of Paris (Yvelines- 78) and in the Nantes region( 44) , the police have thought of a new way of trapping motorcyclists; they send a "normal" motorcycle, in this case a BMW R75 (in other words an old motorcycle) on to the road. Many kilometers behind it are "normal" police motorcycles. The R75 is in communication with the police patrol.
When a biker passes the first bike at a too high speed, the "undercover" police officer radios to the patrol who will then intercept the speeding biker. You'll never even know that you passed the trap until they stop you!
Other regions in France are interested in the experiment and might follow suite shortly.