The chances are that if you are over 20, you will never have heard of it.
But if you are a teenager in the habit of hanging around causing trouble, it could well have sent you and your mates packing.
The Mosquito, which emits a sound that can be heard only by the young, has been quietly clearing shopping precincts around Britain for the past two years.
Yesterday, however, the Children’s Commissioner for England provoked a furious backlash after demanding that the device should be banned – because it is an infringement of yobs’ human rights.
Professor Sir Al Aynsley-Green claimed the device was “demonising” young people, while civil liberty campaigners claimed it breached laws safeguarding the right of free assembly.
Some 3,500 of the £600 devices have been installed by businesses and councils blighted by gangs of intimidating “hoodies”.
A speaker emits an irritating but harmless high-pitched ringing sound at a frequency which is audible to children and teenagers, but which most people lose the ability to hear in their early 20s due to the normal process of age-related hearing loss known as presbycusis.
Teenagers are typically driven away within a few minutes, while adults are blissfully unaware of the sound.
Dogs, for some reason, show no signs of distress.
But the Children’s Tsar is unimpressed. He said: “These devices are indiscriminate and target all young people, including babies, regardless of whether they are behaving or misbehaving.”
The technology symbolised the “malaise at the heart of our society”, he said, promoting “fear and hatred” of young people and “creating a dangerous and widening divide between the young and the old”.
Shami Chakrabarti, of the human rights group Liberty, called for the Government to ban the technology, saying: “These untested, unregulated devices are at best a dog whistle and at worst a sonic weapon directed against young people.”
But Tory MP Philip Davies said: “The good professor needs to come down from his ivory tower and see what it’s like living in the real world.
“My constituents are sick to the back teeth of unruly yobs and the Mosquito device, deployed properly, is hugely successful and a brilliant piece of technology that should be more widely implemented.
“In my village we had an Indian restaurant owner who was plagued by a gang of yobs outside his restaurant intimidating his customers and yelling racist abuse.
“The police installed one of the devices and it solved the problem instantly.”
David Davies, Tory MP for Monmouth, said: “Maybe Professor Aynsley-Green would like to have a group of 50 youths swearing and drinking outside his front door, and see how he likes it.
“In my work as a special constable in Abergavenny I see these louts terrorising law-abiding people and it’s disgraceful.
“I once confiscated some alcohol from some boys and poured it in the gutter when to my astonishment the lad got down on his hands and knees to lap it up.
“The Mosquito device is an excellent deterrent for gangs congregating and hanging around and should definitely not be banned.”
The gadget’s inventor Howard Stapleton said: “People talk about infringing human rights but what about the rights of the shopkeeper who is seeing his business collapse because groups of unruly teenagers are driving away his customers?”
Simon Morris, commercial director of manufacturers Compound Security Systems, said he would welcome a legal test case if campaigners tried to enforce a ban.
“Many of our customers have said they would buy more if the legal and human rights questions were properly resolved.
“We have been lobbying the Home Office and Liberty to work with us on a code of practice, but they won’t engage with us. You have to wonder if the human rights issue is being pursued to the detriment of sections of society who are being plagued by feral teenagers, and in some cases being killed by them.”
The Association of Convenience Stores, which represents 33,000 shops, said it fully defended the device to drive away gangs of youths.
Publication This is London
Date 15 February 2007