The Mosquito emits a high-pitched whine inaudible to the majority of adults over 30, while causing yoof ne'er-do-wells a level of irritation sufficient to drive them from any premises packing the device. Successful trials a couple of years back in a grocery store in Barry, South Wales, and a shop in inventor Howard Stapleton's home town of Merthyr Tydfil, provoked plenty of interest in the product, and there are now an estimated 3,500 deployed nationwide in the fight against anti-social tearaways.The article says that the device causes discomfort to "ne'er-do-wells", but that's only true if you assume that every human being under 30 is a ne'er-do-well. I think this is pretty outrageous and I can't imagine the economics of an area where merchants are happy to drive off every potential customer under 30, just to get rid of potential trouble makers.
Of course, that's their decision if they don't want young customers, but what happens when grandma takes the baby to the store and the kid starts crying for no reason? Grandma doesn't know that the baby is being assaulted by high-frequency sound and doesn't have any reason to think that the baby will stop crying when she leaves the store so she might stay there for an hour, torturing the poor kid.
In the US, they would get their butts sued off the day after they installed one of these horrors. What's wrong with England that this is actually an issue?