One time around 12am, I was awoken by sounds of someone trying to gain access to my room by unsuccessful repeated attempts with the card key. Finally I just got out of bed in my boxers and wife beater and opened the door, it was a Southwest FO. I told him you have the wrong room, he said sorry about that, I proceeded to go back to sleep. I have also done this once or twice mostly because of incompetent front desk. One time I walked in on an old couple sleeping. Another time I walked in on a couple that were awake. Nothing worse than that picture, having an airline pilot walk into your room while you're chilling on the couch. From then on, it's always been bolt/do not disturb sign for me.