Fast and Furious
Obama Administration (D)
Attorney General Eric Holder was held in contempt of Congress after refusing to release all documents that House lawmakers had demanded. The sting operation allowed weapons from the U.S. to pass into the hands of suspected gun smugglers so ATF could trace them to Mexican drug cartels. In the process, ATF lost track of hundreds of firearms, one of which was used to kill Border Patrol Agent Brian Terry in December 2010.
Source: LA Times