You never know what you are going to see on the subway. As I was riding the CTA Blue Line to O'Hare Airport, I noticed the poster on the top. I have seen some strange things on the Chicago trains, but I couldn't figure out what it was advertising. Then I saw the posters above, "period proof underwear." I don't even want to think about what, or how - . . . how is the picture on the top related? What is the strangest advertising you have seen recently?