Last week’s launch of the RMBS Working Group’s website demonstrated that government investigators see Wall Street insiders as a valuable source of information to detect and prove fraud and other misconduct in the packaging of mortgage securities. “Fraud can be hard to uncover without help from whistleblowers who were corporate insiders,” the task force said on the website. Whistleblowers can get rewards of up to 30 percent of the government’s monetary recovery based on the specific information, as well as protection from retaliation. The inclusion of a whistleblower provision in the Dodd-Frank Act has...