Hmmm.....interesting question.

I think that how I feel is this:

Why shouldn't homeless people have pets? These pets would otherwise be at the pound or in a shelter, and we all know what happens there, don't we?
I have seen quite a few dogs with their homeless owners, and I can definately say that they look very devoted to them, and all-in-all happy.
Is a dog who spends most of his life in a back yard alone, or chained-up better off? I don't think so.
Also, it is known that animals bring more contentment and happiness to the people who own them, so maybe the homeless with animals are more likely to get out of their situation...........? Just a thought.

As far as there being homeless drug-addicts, etc. with animals, I don't really see that being too common. Most addicted people live for one thing only, and an animal would not be too condusive to their cause/lifestyle (especially by the time they got to that very low point of being on the street).

I don't know, maybe I am wrong. I Would be interested to hear other points of view.