Fannie Mae and Freddie Mac, the giant mortgage providers brought under government control in September 2008, were nationalized at the height of the financial crisis as more and more homeowners defaulted on their loans. Covering both companies' obligations has already cost taxpayers a bundle and financial experts are now warning that they could require "the mother of all bailouts" if house prices fall further. By the numbers:

$6 trillion
The amount in mortgages either owned or guaranteed by Fannie and Freddie — equivalent to 53 percent of the entire U.S. mortgage market

90 seconds
The period of time between each foreclosure taken over by Fannie and Freddie in the first three months of 2010

The number of houses owned by Fannie and Freddie at the end of March 2010. Seattle has roughly the same number of residential properties.

$145.9 billion
The amount the nationalization of Fannie and Freddie has so far cost the American taxpayer. That's $83.6 billion from Fannie, and $61.3 billion from Freddie.

$389 billion
The amount the Congressional Budget Office predicts Fannie and Freddie will cost the American taxpayer over the next decade. Other analysts have pegged the "worst case scenario" as $1 trillion.

The amount of money it costs the government to sell a house

60 percent
The average loss Fannie and Freddie take on each house they resell

$1 billion
The approximate amount the government spent to maintain the condition of its foreclosed houses last year

Average monthly amount the government pays a contractor to mow the lawn of a single foreclosed home. That adds up to a total monthly bill of $10 million.

Number of years homeowners who now "walk away" from a Fannie or Freddie mortgage will have to wait before being eligible for a new loan.

$93.6 billion
The combined losses of the two firms in 2009

35 cents
Fannie Mae's share price on June 29. In October 2007, the price reached a high of $66.95. Fannie and Freddie have both been forced to delist from the New York Stock Exchange.

Sources: New York Times, CNN Money (2), CNBC, Business Week