This must be a bank's worst nightmare; a homeowner who doesn't care about foreclosure. If there are enough people like Mr. Zulueta, then the very existence of the US banking system is in question. The walk-away home debtors are very dangerous.

When Raymond Zulueta went into default on his mortgage last year, he did what a lot of people do. He worried. In a declining housing market, he owed more than the house was worth, and his mortgage payments, even on an interest-only loan, had shot up to $2,600, more than he could afford. “I was terrified,” said Mr. Zulueta, who services automated teller machines for an armored car company in the San Francisco area.

Then in January he learned about a new company in San Diego called You Walk Away that does just what its name says. For $995, it helps people walk away from their homes, ceding them to the banks in foreclosure.

Last week he moved into a three-bedroom rental home for $1,200 a month, less than half the cost of his mortgage. The old house is now the lender’s problem. “They took the negativity out of my life,” Mr. Zulueta said of You Walk Away. “I was stressing over nothing.”

You Walk Away is a small sign of broad changes in the way many Americans look at housing. In an era in which new types of loans allowed many home buyers to move in with little or no down payment, and to cash out any equity by refinancing, the meaning of homeownership and foreclosure have changed, economists and housing experts say.