You're a homeless person, sleeping on the bench of a bus stop, as you usually do. But this morning, someone's had enough of you taking up the entire bench for yourself. They decided that if you're going to take advantage of the public infrastructure so much, you must give something back to the society. So they tied you to the bench. From now on, you will serve the public as a soft, cushy bench, and in exchange you have a place to sleep and protection from weather over your head. Fair exchange?