Seriously. What the hell is wrong with these people.
They were especially bad in LA, but there are plenty of them here as well. I love people who have giant dogs in small apartments/condos/other things with no yard/etc. They largely fall into the group under discussion.
I had an idea about starting a website that just posts pictures of people who don’t clean up after their dogs. I may still do that someday, if I ever get really motivated, and have the kind of time required to sit around with a camera catching these things.
In conclusion: If you take your dog for a walk, PICK UP THE SHIT! Also, if you don’t have one, you really should consider moving to someplace with a yard, or giving your dog to someone with a yard.