Anheuser-Busch InBev (BUD) crashed 6% Thursday on news that the U.S. government objects to its acquisition of Grupo Modelo on antitrust grounds. Belgium-based Anheuser-Busch said in June it would pay $20.1 billion for Mexico's Grupo Modelo, whose prize asset is Corona, Mexico's biggest-selling beer (and the biggest beer import in the U.S.). But the U.S. Justice Department filed a lawsuit Thursday to block the deal. Why? "The department is taking