Michael Bloomberg seems to have a knack for bringing out almost everybody's inner libertarian. The billionaire mayor of New York has spent an inordinate amount of his three terms trying to take away our cigarettes, trans-fats - and now, the Big Gulp! Even Jon Stewart couldn't resist the path of least comedic resistance, defending his demographic's right to drown itself in buckets of Berry Citrus Slam Slurpee. As a card-carrying free market economist, I'm uneasy about the proposed ban, too. For one thing, it's a bit arbitrary: Starbucks' equally sugary venti (24 ounce) Caramel Frappuccino clocks in at 510 calories,...