If it's on the streets, whatever animal it came from is not human.
Well, the mayor says it's human waste. I have to assume you're dehumanizing street-shitters, rather than expressing a naive faith in your fellow humans.
I don't care if they walk on two legs. If they shit anywhere outside of a toilet or a well-dug hole in the woods, they're animals. That's what animals do.
Wait...so San Francisco is now a sanctuary city for prostitution?