Jingle Mail
From the Default (finance) wiki article:
When a debtor chooses to default on a loan, despite being able to service it (make payments), this is said to be a strategic default. This is most commonly done for non-recourse loans, where the creditor cannot make other claims on the debtor; a common example is a situation of negative equity on a mortgage in common law jurisdictions such as the United States, which is in general non-recourse. In this latter case, default is colloquially called jingle mail – the debtor stops making payments and mails the keys to the creditor, generally a bank.
From the James Wesley Rawles wiki article:
Without setting a specific timeframe, Rawles was one of many who predicted the end of the housing bubble in the United States, urging his readers on August 14, 2005 to “Sell any rental or non-retreat vacation houses that you own. Take your profit now. It is better to be a year too early than a day too late. Keep that money on the sidelines, with at least a portion of it in precious metals. Then after the bubble bursts, you’ll have the chance to step in with cash and buy at perhaps as low as 40 cents on the dollar versus the currently over-inflated prices. When you eventually do decide to buy, concentrate on productive farm land in a lightly populated rural region.”[25]. In August, 2005, Rawles correctly predicted mortgage holders “walking away” from houses and turning in the house keys to their bankers—what has now been dubbed “jingle mail”.