The intelligence court can if wants dish out secret punishment, so according to the Washington Post if they find you in contempt you will be held in a communications management unit, which is basically max security where they put terrorists. You are forbidden from ever talking to anybody while inside and nobody can know you are there, because it would leak the national security secrets of the specific case so basically the secret police make you vanish off the face of the earth until you cooperate.
I guess the next step is a secret law that makes this illegal?