Those Mosquito things are actually very effective – although you do have to deploy them sensibly – some **** put one up next to some council tennis courts, and just left it running 24/7! We were in our early thirties, playing tennis on a Saturday afternoon, and it got so bad we had to pack-it-in and go to the pub. Probably wouldn’t be able to hear it these days 🙂
I think if you fitted one but only turned it on when the kicking became particularly antisocial, that would be reasonable. It would also give you some scalability in your response – climbs over fence having been asked not to: mosquito goes on. It’s not about being a grumpy old man, it’s just about (gently) encouraging a change towards more considerate behavior.
But also – get one of the wee protective cages to go around the unit. In the above tennis incident, if there was a half-brick lying about, the little plastic emitter would have been history.