Inside, mostly; but let them out to roam periodically. It is an honor to own "the king of the neighborhood"! That is the dog that can use any yard, even if that owner's dog is outside at the time.
Just plain wierd, to me. And, no; these are not slums; they are middle to upper-middle class areas.
I was shocked at how many unfenced properties there are here in GA. I was raised in the CA Bay Area and EVERYONE has a fenced back yard.