No Privacy !
When you are living on the street, you don’t have any privacy. Not even the most private things. Many probably think it’s rude to take a picture of a person during their visit to the “toilet” but it’s a part of their everyday life. And if you want to document their living conditions it’s a part of it.
In the West there is a great resistance of taking pictures of homeless, but the homeless or people living in slum in Asia appreciate it. They accept their situation and see it as a way to show the World the miserable conditions they are living in.
I never ask people if I can take a picture of them but after I have been taken the picture I always show them the Image and then start a conversation.
I work with two cameras. One with 35mm to Street Photography Images and one with 50mm to Street Portrait Images. When you shoot Street Images there are no time to chance lenses
Not to seem to intrusive I always shoot single Image, not more then 5-6 Images, more can seem pretty aggressive in my point of view !