My parents were always pretty free with me. They were of the school of thought that if you really cramp down on someone and tell them not to do all these things, it's gonna become like forbidden fruit.
These people living on the streets could have been friends you once knew. They are people who have somehow fallen through the gaps and found themselves, often through unimaginable circumstances, on the cusp of existence. In another reality, this could easily be me or you.