i see this all the time, careless and unnecessary. I only did once, not even sure why, perhaps it was because some one had shoved this leaflet in my hands, a religious document of some sort and not thinking i threw it on the ground. A nice policeman asked me what i was doing, i apologised, and picked it up and placed into a bin. so not i don't throw litter as a rule, and anyone who does is lazy and inconsiderate. People leave their food leftovers on buses and trains, why?