There's got to be a double jeopardy joke in here somewhere

Ken Jennings, famous (?) for multiple Jeopardy wins, has a blog on which he discusses how to write a trivia book that won't infringe copyright. As it turns out, his advice includes a theory that copyright scholars like Wendy Gordon and Jessica Litman have explored in depth: that, for some copyright purposes, statements about artistic products should be treated as facts.