Get a cease and desist order.

YouTube sounds like a great idea! My wife just throws it on their front door, they stop after she does it once or twice. :)

Hey buddy, maybe this story will help: back in my days as an air force brat, my family was living in a community on base. Nice house, nice neighbors, except for one. This guy liked to let his giant MASTIFF walk around and roam the neighborhood. This dog left landmines the size of your head, and they smelled to high heavens. Now, after telling the owner in varying degrees of "don't let your dog crap on my lawn," and not getting the desired results, my father decided to take action. So, one early morning, he gets out his shovel, and starts picking up the monstrous turds. He takes each shovelful and unceremoniously places it in the bed of the offenders pick up truck. As a final insult, he slung a few shovelfuls of shit at the guys front door. That dog never crapped on our lawn again.

Hmmm duh! get a camera film film him, then take the film to the cops! boom

Just go into his yard and drop deuce, then piss in his tank

that's your own fault for not saying anything about it.

Sprinkler system.

But black pepper and hot sauce all over your yard, screw with the dogs nose!

Man up and do something about it.

Yell at them!!