Attorney General Jeff Sessions has told associates he wants to put the entire National Security Council staff through a lie detector test to root out leakers. It's unclear whether this will ever happen, but Sessions floated the idea to multiple people, as recently as last month.
Sessions' idea is to do a one-time, one-issue, polygraph test of everyone on the NSC staff. Interrogators would sit down with every single NSC staffer (there's more than 100 of them), and ask them, individually, what they know about the leaks of transcripts of the president's phone calls with foreign leaders. Sessions suspects those leaks came from within the NSC, and thinks that a polygraph test — at the very least — would scare them out of leaking again.