CBS' 60 Minutes: Prosecute Wall Street (Citigroup Fraud video)

A high-ranking former Citigroup Executive - turned whistleblower says he tried to warn his superiors about defective and even fraudulent mortgages.

This Citigroup whistleblower's warnings were sent directly to top Citigroup executives - including former Treasury Secretary/Citigroup Chairman of the Executive Board Bob Rubin.

So why hasn't Citigroup or its executives been prosecuted? CBS' 60 Minutes' Steve Kroft reports.