Huh?

My daughter came in upset today, she told me that the little boy (who is known for being a terror) put a bunch of glass on the seat of her swing today. I was perplexed. What on earth would make someone do this? It sounded so ridiculous, so I went outside to investigate. I was expecting to see A piece of glass, as in one. What I found shocked me, there was a pile of neatly stacked broken pieces of window panes, old pieces of mason jars tidily arranged on the seat of the swing. It reminded me of the game you play with the blocks. She told me the little boy said with a friend "What happened to your swing?" then as the little rotter ran away he said "We did it!". . . Unfortunately this is not the first time we have had issues with the family, and normally I just ignore it. It seems that again, they have too much time on their hands, and love drama. I personally cannot be bothered with this obtuse bunch. They were very friendly when we moved here, then a woman came up to me and said that they were spreading rumours that we were drug dealers. (As if. . . If we were drug dealers then we would have had a better car, money to renovate, and not stuggling at the time to pay the mortgage). I immediately stopped interacting with them. This irriated them. They also like to (from what people say), phone Children's Aid Society on people who they do not like. I guess this acts as a deterrent to people actually complaining about them. This time, as the "attack" was directed at my daughter, I talked my husband into coming over with me and speaking to the Grandfather. He denied it, the son denied it, (but earlier the sister of the little boy, admitted to him saying he did indeed do it to a neighbour). I was fed up. I said I would appreciate this not happening again, we respect their property (my kids do not run amok and terrorize them), and that we ask the same. Furthermore, broken glass is dangerous. I was polite, but assertive and also briefed him on the property lines etc. This guy is a total putz. Sweet to my face and then was heard briefing his grandchildren accusing us of being liars. Wayyyyyyy too much time on their hands. They should enroll their children in some etiquette lessons, and maybe some parenting lessons that provide the skills for positive reinforcement, instead of yelling in Hick Language at them. We can't even enjoy our backyard.