The Obama administration isn't prosecuting anyone because

They'd have to work from the inside out.  The entire Justice department is a gang of criminals.

http://oversight.house.gov/index.php?option=com_content&view=article&id=1565:doj-official-asserts-fifth-amendment-right-in-refusing-to-testify-in-probe-of-operation-fast-and-furious&catid=22:releasesstatements