Wrong.
The only aspect of last year's meltdown that even remotely resembled anything laissez-faire was the trade in mortgage-based derivatives, which wouldn't have had all the high risk paper in it without insane amounts of outside interference in the creation of those mortgages.
It was the shortcomings of Capitalism due to the greed of people. As for laissez-faire, what you're basically asking for if does actually occur in this country would be a hundred times worse than what happened last year. I wouldn't trust the scumbags on Wall Street as far as I can throw them, giving them free rein is like bending over in front of them so you can **** you in the ass.
Remember, one of the reasons all of this came about was the deregulation.