Although some people just can't even be shamed into proper behavior.

I frequently take my dogs to the dog park. There are probably at least a couple of hundred dogs visit over the course of a typical day. Every time I'm there I go around and pick up dog poop that other owners don't bother to pick up. Averages 25-40 per visit. So a lot of dog owners are not responsible and just plain do not care. I'm going to have a clean dog park even if I have to do it myself. Thankfully, I'm not the only one who regularly picks up after others.

Every dog owner who comes to the dog park well knows they are responsible for picking up after their dogs. They've all certainly been reminded enough times. It's understandable that a person is not going to watch their dogs every minute so they won't see every deposit their dogs make. So would it be too much to ask for each dog park visitor to get one of the provided plastic bags and go pick up a couple of deposits? Seems like that is the least that a person could do. But many people just will not do it.