Yep, the idiots who bought more house than they could afford, the lenders who didn't do due diligence in lending money to people who couldn't pay them back, the brokers who decided to "package" mortgages and sell them as derivatives, AIG for deciding that it would be a brilliant idea to "insure" the derivatives, and the various governments around the world (cuz it's not just us who are in this mess) who turned a blind eye to the irresponsible and barely legal shenanigans that were going on.
And in some cases - (ahem the afore mentioned - Barney Frank) exacerbating them:
http://www.youtube.com/watch?v=hxMInSfanqg