If there "is evidence", you should provide it.
http://www.breitbart.com/Big-Government/2013/06/04/National-...
Testimony: http://waysandmeans.house.gov/uploadedfiles/eastman_testimon...
http://www.propublica.org/article/irs-office-that-targeted-t...
I'm not convinced it's a targeting of opposing political groups by the white house though. If Propublica requested papers, and got them even if they shouldn't have, that's a bureaucratic error.