“In order to work with a Security Clearance for the FBI, CIA, NSA, or Border Patrol you have pass a drug use and lifestyle polygraph examination.”
And Brennan, Comey, McCabe, etc, all passed with flying colors. If you need more evidence that polygraph is a fraud...
But none of us know how many have been caught in lies. Nor do we know what questions are being asked in order to qualify for a security clearance.
Just because you don’t lie under polygraph examination doesn’t mean you won’t lie later on.