CNET: Does a Secret Law Require ID for Air Travel?

The U.S. Attorney General apparently claimed to the 9th Circuit U.S. Court of Appeals that a “secret law” of some sort requires air travelers to show identification before they can fly. Although admitting the peculiarity of the claim, the AG claimed it can show the law to the court under seal to the court, but not to opposing counsel, and would not allow it to be described.

Where are we, again?