I think its the owner's responsibility to keep their dog safely contained, and sometimes that involves use of a chain. I always opted to crate my dogs in the house. Some people feel as though that is inhumane. Other people use kennel runs. I don't really care what it is as long as it keeps the dog safe and secure at home. If a person is going to chain the dog, they have to take different precautions than one who keeps their dog inside, but that doesn't make it any less humane IMO. We need to remember, too, that plenty of people keep multiple dogs that don't get along, and they have to use the tools available to them to keep those dogs apart while they're away.