We've seen the Obama campaign going after Mitt Romney for his time at Bain Capital. I think with the Olympics approaching we're about to hear more about this story from them very soon. From Up With Chris Hayes: Mitt Romney and federal money for the Olympics:

Up host Chris Hayes and his guests talk to former Salt Lake City Mayor Rocky Anderson about the federal assistance Mitt Romney sought as head of the 2002 Salt Lake City Olympics.

I clipped the interview down to the portions with Anderson. You can watch the entire segment at the link above. Here's more from the Daily KOS on Romney's time running the Olympic games: Romney's Olympics: