Do you have some ID?
Do you need government-sponsored identification to fly in a plane in the U.S.?
John Gilmore wanted to fly in the U.S. without showing government sponsored identification and without submitting to an extensive search. His appeal to the Ninth Circuit Court of Appeals was rejected. At issue were the Transportation Security Administration directives, which are unpublished, change frequently and are often not available in writing. They are also not available to air travel passengers who often face confusing and conflicting situations. However, as part of the Court's decision, they did state that the current law "requires that airline passengers either present identification or be subjected to a more extensive search."
While Gilmore lost his appeal and hasn't flown in the U.S. since, he did issue a challenge to the Department of Homeland Security's privacy advisory committee in San Francisco: mail your driver's license home and "attempt to fly home without identification." One person took him up on the challenge. He made it.