Someone from the UK just found this site by searching for "device to stop young people congregating" using a mobile phone provider's search engine. Now, I know, I know, there may be an important backstory behind that person's search. Some people apparently really do have problems with kids intimidating them (e.g. see these comments on the Mosquito) and believe that a technological solution is the only answer.
But take the concept in isolation: how will history judge the "device to stop young people congregating" concept? Will it be seen as a cruel, archaic display of embdedded prejudice, in the same way that we would be horrified to see "device to stop X race of people congregating" or "device to stop X colour people congregating"?
Or will it be seen as a mild, thin end of a much larger, more sinister wedge ("device to stop ALL people congregating")?