Sort of common to remove shoes in certain parts of the world, heck I go barefoot around the house pretty much 100% of the time, what I don't do is plant my feet on the wall. Despite how clean we keep our home, hands and feet tend to pick up oil and other stuff from the street. Just seems odd to me that some idiot would think it ok to do something he/she wouldn't do at home. I give my kids a hard time if they feel the need to grab the wall, as over time it builds up marks.