Is there some sort of a misconception about how these devices work? All it does is emit a high frequency pulse. If it's on permanantly and not just at the store owner's disgression, it won't become a real nuisance unless you're under 20 (or just have good hearing) and hang around outside said store for a considerable amount of time. It's meant to stop chavs hanging around outside shops for a considerable amount of time, not to physically disable people who walk past or even live next door to the shop.
These aren't new either; they've been in use outside stores accross the country for some time now.
