A new device used by British merchants to prevent teenage loitering around their stores is stirring up controversy among civil liberties groups, reports [1]The Washington Post.

The device, known as the Mosquito, emits a high-pitched, piercing squeal that can only be heard by people under 25. According to its U.S. distributor and its U.K. manufacturer, Moving Sound Technologies [2] and Compound Security Systems [3]:

The Mosquito™ ultrasonic teenage deterrent is the solution to the eternal problem of unwanted gatherings of youths and teenagers in shopping malls, around shops and anywhere else they are causing problems. The presence of these teenagers discourages genuine shoppers and customers’ from coming into your shop, affecting your turnover and profits. Anti social behavior has become the biggest threat to private property over the last decade and there has been no effective deterrent until now.

The Mosquito uses the health of a youthful human ear against itself. As humans age, reports the Post, "hair cells in the inner ear start to deteriorate and so does the ability to hear high pitches." Kids, brimming with robust hair cells, hate the device, leading Britain's children's commissioner, Al Aynsley-Green, to join a coalition of civil liberties groups advocating its ban. Kathleen Marshall, Scotland's children's commissioner, says the device "is a war on young people."

But police and store-owners hail the Mosquito and provide statistics to prove the effectiveness of the device. Police in Merseyside, England, have rigged the Mosquito to their patrol cars and use it to break up youthful mobs engaging in antisocial behavior. Disruptive behavior fell 60 percent in some areas, according to a police official interviewed for the story. One store-owner says the Mosquito cut petty crime in his store by 80 percent.

The Mosquito's manufacturers have sold 3,500 units in Great Britain, while an additional 200 have been sold in the United States. The device costs $975.

While the Mosquito appears to be an effective anti-loitering device, the question remains: does it infringe on teenagers civil liberties? And are there other methods store-owners can use to prevent loitering without offending the ears of their targets? Let us know in comments [4].