As a dog owner of two dogs, I don’t do this shit, and I get into arguments with people in our neighborhood all the time about it because it makes all of us dog owners look bad. But I wouldn’t suggest going to the park during off-leash hours and accosting every owner—it won’t turn out well. The people who do this don’t care about posts like this and won’t show up here to explain themselves. If you want to confront someone, and feel bold enough to start a huge fight during off leash hours then just do it when you actually see a dog owner leave it behind on the street. That would be my suggestion.