Dog poop is turning into spite, do I dare...

So my neighbor has confronted me once about the dog poop in my back yard. I clean it up but usually once every 3–4 days. Now I live in a town house and there isnt much backyard. All the neighbors have about 5×7 feet of backyard and it all connects. So I go out today and smell toilet bowl deodorizer which you can see sprinkled in her yard and I see poop on my front step. Now I know my dog didn’t poop right where I would step out to walk. I think its clear it was planted so that i step in. The rage I’m feeling makes me wants to pick it up and right something on her patio door with it. However I won’t take it that far!. Now I realize nobody likes poop and that if you don’t have a dog its very gross(even with a dog its gross) HOWEVER its my backyard and I should be able to do as I please with it. So I am thinking about getting some rope and some sticking and going around the perimeter of it this way my dog stays in his area(which he usually does anyways) and putting a sign that says please keep mind your own Fing business! – is that taking things to far? I see a feud beginning here!