Interesting point:

And given that nearly a quarter of mortgages are underwater, and that 10 percent of mortgages are delinquent, White, of the University of Arizona, is surprised that more people haven’t walked. He thinks the desire to avoid shame is a factor, as are overblown fears of harm to credit ratings. Probably, mortgagees also labor under a delusion that their homes will quickly return to value. White has argued that the government should stop perpetuating default “scare stories” and, indeed, should encourage borrowers to default when it’s in their economic interest. This would correct a prevailing imbalance: homeowners operate under a “powerful moral constraint” while lenders are busily trying to maximize profits.

Oh, yeah: I'm back, baby!