WASHINGTON - OCTOBER 21: The headquarters of Fannie Mae are seen October 21, 2010 in Washington, DC. The Federal Housing Finance Agency announced today that U.S.-backed mortgage firms Fannie Mae and Freddie Mac, which have already required $148 billion in bailouts, may now need up to $363 billion in taxpayer-funded Treasury Department aid under worst-case scenarios. (Photo by Win McNamee/Getty Images)
