Mosquito sounds to avoid teenagers loitering

The IHT has a strange story about a device, called the Mosquito ("It's small and annoying,"), that emits a high-frequency pulsing sound which can be heard by most people younger than 20 and almost no one older than 30.

So far, the Mosquito has been road-tested in only one place, at the entrance to the Spar convenience store in this town in south Wales. Like birds perched on telephone wires, surly teenagers used to plant themselves on the railings just outside the door, smoking, drinking, shouting rude words at customers and making regular disruptive forays inside. "On the low end of the scale, it would be intimidating for customers," said Robert Gough, who, with his parents, owns the store. "On the high end, they'd be in the shop fighting, stealing and assaulting the staff." (...) The results were almost instantaneous. Where disaffected youths used to congregate, now there is no one. (...) Stapleton is considering introducing a much louder unit that can be switched on in emergencies with a panic button. It would be most useful when youths swarm into stores and begin stealing en masse, a phenomenon known in Britain as "steaming."

Kind of scary, will we see that in France to avoid car fires?