Obviously, this is a well-meaning idea.  However, I wonder how 'efficient' such a tactic would be.  It might take years for a person to get into a position to be able to obtain and leak information.  And, the longer a 'mole' stays, the more he will become dependant on that government.  And, let's not fall into the trap of assuming that everyone who works for a government agrees with the policies and practices of that government.  If we guesstimate that 1% of (current) government employees would be sufficiently unhappy to do such leaks, 

If Snowden or Manning, or both, get a well-publicized $5 million reward, that would invigorate a lot of similar people to do similar things.  What's desirable would be a kind of anonymous reward system to allow ordinary people to reward the leakers.

  I haven't read enough about the origins of Wikileaks to know whether such a system was ever contemplated.
         Jim Bell