Once as a kid, I was walking by a house (actually several, but one in particular caught my attention) - I heard some loud knocking which caused me to look up at the window. There stood this young man naked. In that case, obviously it was quite different. I was on the sidewalk walking home in the middle of day and this boy was obviously trying to capture my attention through knocking loudly.
I didn't say nothing to anyone. However, several days later, this teenage girl had this same boy drop his drawers right in front of her - after that we never saw the boy again.
