The line between art and pornography has long bedeviled art historians, the Supreme Court, and, yes, CBS. While it’s obvious we’re not about to see some Robert Mapplethorpe photographs (um, NSFW) on network TV, what about a Modigliani? A Picasso? Or Michelangelo’s David? Last night, Stephen Colbert showed just how convoluted these lines can be. Like, we mean literal lines, where first he draws boobs and then a face. Is it boobs, or is it a face? Boobs? Face? Whatever it is, it’s art.