So, I was out taking portraits of people. I had been asking each and every subject if I could shoot them, and most were happy to let me. Then I came upon an elderly woman who seemed like an interesting subject. I asked for her permission and she said okay--as I was taking her picture, I engaged her in friendly discussion and soon found out she was homeless. I wound up buying her a couple of sandwiches and some bottled water. She seemed very appreciative. From my understanding, there is some ethical rule in photography against taking pictures of the homeless as it constitutes a form of exploitation. How would you have dealt with the situation? Keep in mind, I am only taking pictures for personal use.