The federal agency overseeing Fannie Mae and Freddie Mac failed to act on almost 100 complaints filed from July 2008 to October 2010, pertaining to possible foreclosure abuse and mortgage fraud at the taxpayer-owned mortgage finance agencies. The companies did not refer the complaints to criminal investigators or other law-enforcement authorities, according to a report issued late Tuesday by the inspector general of the Federal Housing Finance Agency.   Louise Story, Wall Street and finance reporter for The New York Times, speaks with us about this news.