It's a complicated problem that comes down to which lien takes precedence, and the previous administration attempt to help people who are in over their head due to second mortgages was a failure. The program was also stymied by the unwillingness of banks to take losses on the loans:

Programs to help distressed borrowers so far have focused on lowering the payments on their primary mortgage. But during the go-go years of the housing market, millions of homeowners took out a second or even third loan backed by their home. Many were piggyback mortgages, which enabled home buyers to put little or no money down, while others took advantage of rising home prices to secure home-equity lines of credits.

Now, these secondary loans are aggravating the foreclosure crisis, adding an extra burden that can be the difference between borrowers digging out of debt and losing their home. The extra mortgages also make it far more unwieldy for lenders to untie the knot of excessive debt and provide relief to borrowers. And even when borrowers do get help with their primary mortgages, the second loans can continue to bedevil homeowners, raising the risk they will default later.

The Obama administration is about to ramp up its efforts to tackle second mortgages as part of an aggressive program announced by the White House on Friday to address foreclosures. Other steps include a requirement that lenders offer temporary mortgage relief to unemployed borrowers and increased incentives for lenders to cut loan balances for borrowers who owe more than their homes are worth.