The government has handed its ATM card to beleaguered mortgage giants Fannie Mae and Freddie Mac. The Treasury Department said Thursday it removed the $400 billion financial cap on the money it will provide to keep the companies afloat. Already, taxpayers have shelled out $111 billion to the pair, and a senior Treasury official said losses are not expected to exceed the government's estimate this summer of $170 billion over 10 years. Treasury Department officials said it will now use a flexible formula to ensure the two agencies can stand behind the billions of dollars in mortgage-backed securities they sell...