Their money monkeys, in an infamous meeting with "financial engineers" from Goldman Sachs and others, are the ones that INVENTED the whole subprime/tranche mortgage packaging scheme that has caused this disaster...
Subprime and tranching are two different, but related things. Tranching mortgages of high-credit-quality borrowers is actually a good thing, net-net. Tranching mortgages of deadbeats? That is complete idiocy.