A word about rude people in Sistine Chapel.
You absolutely, positively can not take a picture in the Sistine Chapel for the aforementioned reason: it will ruin and fade a great masterpiece. Also, the room is huge, it is a chapel meant for reverential pause and it is quite poorly lit. Which means Mr. and Mrs. Rude Tourist from many nations that the picture you take surreptitiously will look like crap. Actually, it will looked like muted dog crap. So buy a postcard in the gift shop outside the chapel and don't be a scummy, art-ruining dirt bag.