CNNMoney recently highlighted a few companies that walk “homeowners” through the process of walking away from their mortgages, and there are a number of practical considerations that might make it a bad idea. If you live in a recourse state, the lender might sue you for the amount of the mortgage that the sale of the property you give back to them doesn’t cover. So if you owe $500,000 on the mortgage and the bank only recoups $150,000, they might come after you for $350,000 in a lawsuit if you have that money available in non-retirement assets. So walking away in a recourse-state is probably not a good idea if you have a lot of money.
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But in non-recourse states — Alaska, Arizona, California, Connecticut, Florida, Idaho, Minnesota, North Carolina, North Dakota, Texas, Utah, and Washington — the bank has no recourse beyond the repossession of the property.

There are, however, ethical considerations.