Watch out for underwater mortgages in Spain

From this article it appears that if you have the unfortunately luck to end up underwater in your mortgage (where the loan-to-value exceeds the permitted values), the bank can force you (after an independent appraisal) to either

1. Extend the mortgage to pledge other assets as collateral
   
2. Pay off enough of the mortgage to bring it into compliance
   

If you do neither of these things within two months, the debtor has “chosen” to immediately repay the entire mortgage.

Ouch. I'm not sure how often this would happen in practice though.