Lenders putting a halt to Buyers buying a home first & then defaulting on their home which is Underwater

“Buy and Bail” homeowners get past loan restrictionsReal estate professionals call it “buy and bail,” acquiring a new house before the buyer’s credit rating is ruined by walking away from the old because it’s “underwater,” or worth less than the mortgage. It’s an attempt to escape payments on a home whose value may never recover while securing a new property, often at a lower price with a more affordable mortgage.

http://www.bloomberg.com/news/2010-08-10/-buy-and-bail-homeowners-get-past-mortgage-hurdles-from-fannie-freddie.html