Start here, the Community Reinvestment Act...
The Community Reinvestment Act (or CRA, Pub.L. 95-128, title VIII, 91 Stat. 1147, 12 U.S.C. § 2901 et seq.) is a United States federal law that requires banks and savings and loan associations to offer credit throughout their entire market area and prohibits them from targeting only wealthier neighborhoods with their services, a practice known as "redlining." The purpose of the CRA is to provide credit, including home ownership opportunities to under-served populations and commercial loans to small businesses. It has been subjected to important regulatory revisions.
Let me see if I can simplify that, the C.R.A. requires banks to give mortgages to poor people.
The hell you say?!?
The new rules, during a time when many banks were merging and needed to pass the CRA review process to do so, substantially increased the number and aggregate amount of loans to low- and moderate-income borrowers for home loans, some of which were "risky mortgages."
Lets look at some video, shall we...
And one more, just for fun.