In a nearby town in RI neighbors on one street had a similar thing going on. One neighbor upset that children's balls would frquently go into his yard. About a week ago during a child's birthday a ball went into this neighbor's yard. He came out and began yelling (a former cop by the way). Neighbor (dad of birthday child) came over, words escalated to fight, which escalated to neighbor shooting and killing birthday child's dad (a city firefighter)! Would it annoy me? Probably. Would I speak to family? Not sure, but probably not. I also grew up in a neighborhood where we played in everyone's yard. My kids have done the same where we live. They gorw up fast and leave. I wouldn't want to have angry older teens as neighbors. It could make life miserable. If you are truly that bothered by this I think a fence is the way to go. I would expect to hear balls hitting the fence once it is up though.