There seem to be some problems with this as a plan even it it stays within bound:
First, nobody who is a follower of any of the targets is going to take the NSA's word on anything against a simple denial and claim that it's all an evil American set-up by the target, which would probably just bolster him.
Second, if the NSA tries to feed it through CIA to a source in the Islamist movements to hide their role, it'll most likely get their cat's-paw busted and fed into a plastic shredder...or turned again to become a triple agent.
Third, this whole scheme is based on discrediting Islamist leaders with the devout population. Organizations like AQ and its affiliates aren't really supported by Joe Arab and all the other devout goat-herders' unquestioning love and enthusiastic support of them, they depend on internal loyalty and deal with the populace by fear of retribution if they don't get whatever support they want.
The whole thing is based on a Western ethnocentric view of a world where rumors and spicy leaks to a relatively-free and unafraid press can destroy someone politically. The Islamic world doesn't work that way.