Let’s hope this doesn’t inspire him to take his political activities out of the shadows and become directly involved in politics: Billionaire David Koch—the subject of a recent profile in the New Yorker as one of the “billionaire brothers who are waging a war against Obama”—has passed New York City Mayor Michael Bloomberg to become New York City’s richest man. He comes in at number six on the new Forbes 400 list, with a fortune of $21.5 billion. Bloomberg’s $18 billion fortune places him at number 10 over all. Koch’s fortune comes from Koch Industries, which has interests in pipelines, refineries, Lycra, and Dixie Cups. His $21.5 billion fortune is tied with his brother, Charles, whom he controls Koch Industries with.