City officials and housing advocates here and in cities as varied as Buffalo, Kansas City, Mo., and Jacksonville, Fla., say they are seeing an unsettling development: [Banks / Borrowers] are quietly declining to [take / surrender] possession of properties at the end of the foreclosure process, most often because the cost of the ordeal — from legal fees to maintenance — exceeds the diminishing value of the real estate.
The so-called [bank / borrower] [walkaways / holdouts] rarely mean relief for the [property owners / banks], caught unaware months after the fact, and often mean additional financial burdens and bureaucratic headaches. Technically, they [still owe / are owed] on the mortgage, but as a practicality, rarely would a mortgage holder receive any more payments on the loan. The way mortgages are bundled and resold, it can be enormously time-consuming just trying to determine what company holds the loan on a property thought to be in foreclosure.
[...]
“It is what some of us think is the next wave of the crisis,” said Kermit Lind, a clinical professor at the Cleveland-Marshall College of Law and an expert on foreclosure law.

Banks Starting to Walk Away on Foreclosures [The New York Times]