From what I can tell, hiring and security procedures for the NSA, CIA etc. are so obsessively paranoid (perhaps with good reason) that they only allow obedient think-inside-the-box employees, never quirky rule-breaking geniuses like Richard Feyman, Alan Turing, or Sidney Reilly.
Is that true? If not, how do the eccentric, rebellious, geniuses agree to and succeed in passing through the hiring procedures, and then how do they manage to do any work which is off the well-beaten (and management-approved) path in that environment?
People who work in the intelligence community and related areas tend to be highly intelligent, diligent, and often patriotic, but don't confuse that for being so blinkered and obedient that they can only think "inside the box." That's not the case. I've worked with those in multiple parts of the intelligence community in ways both meant to foster and requiring creativity and have found it to be a rewarding experience.
That said, if you want to find the real mad scientist types, you need to look at DARPA/IARPA ("advanced research projects" for defense and intelligence communities respectively). The level of creativity and genius in many of the people and projects conducted under their auspices is unequaled anywhere. Most of this work is done by non-government employees, requires no clearance (though of course the really interesting stuff happens behind closed doors), and is probably further "out there" than most can imagine.