Under Timothy Geithner, the U.S. Treasury dismissed the notion that the biggest banks remained too big to fail. His successor, Jack Lew, initially showed signs of toeing a similar line, but since taking over as Treasury Secretary has displayed a "significant change in attitude," says Neil Barofsky the former inspector general of the Troubled Asset Relief Program and author of Bailout: An Inside Account of How Washington Abandoned Main Street While Rescuing Wall Street.