as many as 20 million householders may "walk" from them ...

Americans 'walk' from loans | * David Hirst | * December 23, 2007
...
That one company could downgrade 27 major financial institutions in one stroke is stunning, but it follows a swathe of credit downgrades that swept the US on Thursday and Friday.
...
The depth of the housing crisis was underscored by the head of one of America's largest banks, Bank of America, the straight-speaking Kenneth Lewis, who warned of a completely new attitude by Americans to their homes amid fears that as many as 20 million householders may "walk" from them, further deepening the crisis.
...
A number of factors are at work. First, many mortgage companies, encouraged by Alan Greenspan during 2002-03, ended mortgage deposit requirements.

Then the banks "sliced and diced" and sold the mortgages in packages so the householder no longer owed their payments to their bank but to anonymous international conglomerates.

Mortgage companies have also, by selling "liar's loans" and "toxic" mortgage debt, lost moral authority. Householders see no reason to be loyal to them. ...