Felons, Felons, Every One: Those Who Give Aid and Comfort to Felons...

US CODE TITLE 18, PART I, CHAPTER 1, Sec. 1., Sec. 4., via Atrios

Sec. 4. - Misprision of felony

Whoever, having knowledge of the actual commission of a felony cognizable by a court of the United States, conceals and does not as soon as possible make known the same to some judge or other person in civil or military authority under the United States, shall be fined under this title or imprisoned not more than three years, or both.
High crimes. This isn't lying about consentual sex, folks. This is striking a blow against national security, and then covering it up. This is an utter disgrace.