In our area, if a dog is being a nusance with barking, you can report them. Maybe if people in your area started doing this, the owners would get the idea. Either let the dog in or find a home for it.
It is sad that they keep this dog outside. I know of a breeder that does this and I think that it is very sad. Yorkies are people dogs and don't like to be left alone. They are being very neglectful. You don't get a dog just to feed and water it, you get a dog for companionship. Obviously these people just can't fit this little baby into their lifestyles and that is sad. If they can't love and care for it the way that it deserves, maybe they should find someone that will.