While Flynn was given clearance by the Obama administration for some specific access to security information, Flynn wasn’t given a White House security clearance that is performed by the CIA which vets National Security Council appointees.  That White House security clearance is a much broader security clearance.  Trump's claim that that Obama granted Flynn the "highest security clearance" is a lie and another mis-step by Trump's transition team in the proper vetting of Trump's cabinet.  Once again instead of being transparent Trump resorts to deception.