From this:

...a bill has been introduced in Congress that would prohibit financial institutions from providing home mortgages to anyone who lacks a Social Security number. The bill, introduced by Rep. John Doolittle, R-Calif., would amend the Truth in Lending Act to make ITIN mortgage lending illegal.

Needless to say:

Proponents of ITIN-based lending to home buyers say Doolittle has it all wrong.

Tim Sandos, president and CEO of the National Association of Hispanic Real Estate Professionals, said Doolittle's bill would be "extremely disruptive" and affect far more people than the illegal immigrants the measure purports to target.

Sandos estimates that there are as many as 7 million to 8 million resident aliens in the United States who do not have Social Security cards but are in some phase of the immigration process leading to citizenship...

I'm not entirely sure, but I highly doubt his numbers since legal immigrants can get SSNs. Other quote sources with cash and/or racial cows in the fight are Geoffrey Cooper, director of emerging markets for MGIC Investment and Janis Bowdler, senior housing policy analyst for the National Council of La Raza. If you want to fight corruption, support the bill.