Once or twice should be forgiven, but if it's a pattern, I'm with you. I blame the lazy woman who let her dog use the neighbor's yard (and probably trained the dog to do just that) as much as I blame the woman who overreacted. It's sufficient to scoop the mess up and place it on the owner's front porch, mailbox, car roof (or better location with a convertible), or in their swimming pool. You don't take your frustrations out on a dog just because the owner is a bad neighbor.
Sounds lke work; and more than likely, the same lazy disrespecters who weaponize their dogs would persecute the elder who dumped the anti-private-property bad neighbor's own nasty dog poo back where it belongs. People don't seem to understand the effort it takes an 80-year-old to keep digging yellow spots and replacing topsoil and grass seed in their yards from defiant gibsmedat neighbors' darling dogs. Yet if the 80-year-old's yard looks nasty, the neighbors yell about that and call the local gubmit enforcers.
Our municipality has leash laws. Dogs cannot run loose anywhere you do not own. People refuse -- refuse -- to observe those laws. Children and smaller animals get threatened or harmed by loose dogs. Lawns and expensive shrubbery get used as toilets. Fights break out. Lawsuits happen. Welcome to post-America.
Worst case scenario, smear the dog’s feces on the stucco near the dog owner’s front door. Let it get into all the nooks and crannies. It can be hosed off so it won’t do any lasting damage, but it’ll stink up the porch and require enough cleaning time that the message won’t be lost on the owner.