We had a neighbor who was a great guy. Well over six foot tall, wild mane of hair, and looked like Hagrid from Harry Potter. He was also a bit "Off" from combat tours in the middle east. He owned an empty patch of woods aside of his house.. He had continual issues with another neighbor who would walk his big dogs across the street, and allow them to crap on my buddy's lot, where he thought he was hidden by the woods. He tried talking to the dog owner, and posting signs, but the guy wouldn't stop. One day Hagrid see the dog owner walk across the street, and hold the leash while his dog takes a dump. Hagrid walks over and says, "Did you know I was a decorated shooter in Iraq, and can blow apart a cantaloupe at a thousand yards, every single time?" . At this point dog owner is wondering if he is in danger. Hagrid continues, " I've asked nice, and not so nice, and you just seem to be ignoring me. The next time I see you over here, watching your dog shit on my property, here is how it's gonna' play. You will feel the blood spray first. The mutts head with basically vaporize, and then you will hear the sound of the shot. You will be holding a leash attached to a bloody headless stump. Are we clear?". Now, Hagrid would never hurt a fly, much less kill a dog, but the neighbor didn't know that, and suddenly decided to completely fence his own back yard in, so the dogs could crap in his yard, and never accidentally wondered across the street.
Some people just need a good talkin' to, to resolve an issue like that.