US has secret law requiring airport ID but will not reveal the statute to the public or even the court: “Can Americans be required to show ID on a commercial airline flight? John Gilmore, an early employee of Sun Microsystems and co-founder of the Electronic Frontier Foundation, says the answer should be ‘no.’ The libertarian millionaire sued the Bush administration, which claims that the ID requirement is necessary for security but has refused to identify any actual regulation requiring it.

A three-judge panel of the 9th Circuit Court of Appeals seemed skeptical of the Bush administration’s defense of secret laws and regulations but stopped short of suggesting that such a rule would be necessarily unconstitutional.

‘How do we know there’s an order?’ Judge Thomas Nelson asked. ‘Because you said there was?’

Replied Joshua Waldman, a staff attorney for the Department of Justice: ‘We couldn’t confirm or deny the existence of an order.’ Even though government regulations required his silence, Waldman said, the situation did seem a ‘bit peculiar.'” (CNET)