Da Vinci Code author Dan Brown has become the kind of celebrity who has trouble going out in public. “Gone are the days when he could sit undisturbed in the Grand Gallery of the Louvre, sketching out the murder scene that opens his blockbuster novel. He has stopped taking commercial flights because of the commotion that usually accompanies him, with people lining up in the aisle to get his autograph on books, cocktail napkins, even the occasional air-sickness bag.”