See this article in The American Spectator which lays out a persuasive description of how we got into the current financial mess. Their conclusion: the government was at fault.
Government was at fault, not for under regulating but for over regulating. At fault for pressuring lenders into making loans to poor persons who manifestly could only repay them under very special circumstances. Those circumstances: continuously rising home prices. As soon as home prices stopped rising, mass defaults were inevitable.
So...home prices stopped rising and the inevitable happened. That's why, as a conservative, I'm not opposed to government bailing out banks. Because the trouble banks are now in was caused by our government.
We live in perilous times.