Is this a Carnival thing? I have never encountered too much chair hogging except for on gay cruises, where they put their towels down on the chair as soon as they are redistributed once the disco on the pool deck is over shortly before sunrise. I've sailed Princess twice and not had any problems. Maybe the old people don't like sunning themselves so much?
I do love the concept of the post-it notes, if you're going to hog it, then be ashamed of yourself!
I'm on the Carnival Destiny and can't wait to see what non-white-glove treatment is like!!!