ULPT Request: Ruining petanque game for old people

So, this will seem weird, but in my area a "senior park" was build. I found it very cute at first that some folder people started to go there to play petanque. Unfortunately, they found common enemy, dog owners. There is a large community of them where I live, me including and they literally start attacking people for their dogs. I came to them to tell them, that if they have a feeling I am doing something wrong, they are free to call the police, however I will not tolerate being shouted at with slurs. It got funny, some of the 60 year old grandpas starting throwing fists at me and attacking me. It is the second occasion I know about when they got physical - first one was 75 year old lady, which they were holding "until the police will come". I could solve it by fight and get away with it in this country, it just feels very weird to punch grandpakarens, even in self-defense.

Open to anything, I do not mind them knowing it was me who did "it", however it must be done in a way that wont get me to jail.

EDIT: Please, I am trying to find solution other then physical violence. Aside of obvious reason, being the guy that they are afraid of solves the problem only for me, not the old ladys with the dogs.

EDIT 2: As I understand that the first thought comes to spreading dog shit, glitter, loud music etc., there is also a kids playground very near and other facilities for exercising. I am happy for life if my neighbourhood, so I want to, metaphorically, "spread shit only on the Karens". This puzzle need creativity :)