In order to get in to the Capitol Visitor Center to see the movie, exhibits, and take a tour of the Capitol, you need to have a small white square sticker with a date and time stamp affixed on your person. Oftentimes, the stickers remain on until someone notices that they should be removed. Apparently the point that everyone notices they forgot to remove the sticker is on a sign across the street from the American Indian Museum. It actually looks like an accidentally created work of art - to me. Some stickers were very worn while others were recently placed. It just goes to show you that people sometimes like to copy what others do before them. It's obviously not harmful, but could potentially get quite messy, depending on your point of view.