I agree some people are extremely inconsiderate. The other day I was on the look out for whoever walks their dogs in front of our house and leaves a big pile in our front yard. Daily I had to go out and clean up somebody else's dog doo. I took to watching out the front window whenever people passed to find the culprit and I did. I came outside and said "Hey! You aren't going to leave that in my yard are you?!! She said "Oh no, I was going back to my house to get a baggie". Yeah, right. I said, "Thank you very much" and she came back in about ten minutes and picked it up and hasn't been back since. We don't have a dog park here but we do have a huge fenced in back yard Sophie loves to run in. We also take her for walks and we live on Lake Michigan so she goes to the beach to run. The beach is fairly deserted this time of year and she likes being there. I don't think I would take her to a dog park even if we had one for reasons mentioned here.
Jackie & my 
Sophie 