Should Fannie and Freddie real go bankrupt, they'd leave a "hole" of 5000 billion US$; half of the entire public debt of the United States of America. So the Federal Government shall intervene, nationalizing them and helping them fill up their debt with an increase in taxes for the populace and an increase of the cost of money. It's like, to say, if tomorrow half of all societies quoted at the Italian Stock Exchange should go bankrupt. Fannie must rembourse about 216 billion dollars within 1 year; 291 billions are due from Freddie. There are no money, pretty simple: nobody pays their loan/mortgage fees any longer, and nobody opens new ones. There's no real estate market any longer. People has no more money.
What's astonishing is that the true crisis hasn't arrived yet. The banks risking bankruptcy in the United States are about 90, excluding IndyMac that's already gone belly up with the third worst bankruptcy in the history of the United States since World War 2.
Some suggestion: buy no real estate properties, make no debts, open no new loans/mortgages, close them if you have them if you can, don't buy stocks of real-estate societies and sell them out if you have them. And brace for impact.
"It is criminal to teach a man not to defend himself, when he is the constant victim of brutal attacks. It is legal and lawful to own a shotgun or a rifle. We believe in obeying the law." -- Malcolm X
"We (atheists) act in good conscience because we believe in moral principles, not because we expect a reward in Heaven." -- Margherita Hack