There may or may not be a rule requiring ID in order to board a plane in the US, but we can't tell you that, because if it exists it's classified. "We" here being the US Department of Justice, which appears to have been smoked out by Electronic Frontier Foundation cofounder John Gilmore. Gilmore's argument that the ID requirement is unconstitutional is perhaps a little extreme, but the Feds' refusal to say publicly whether or not it exists is a plot line worthy of Franz Kafka.
Wired reports that on Friday DoJ lawyers filed a request to present the rebuttal to Gilmore's case in secret, saying that if a requirement for ID exists then it would be in a classified security directive, and therefore could not be revealed in open court.
The case has already been decided against Gilmore in the district court, but he is now appealing. The DoJ motion, available here, points out that the district court decided the case on the government's motion to dismiss, and that "all parties and the court simply assumed the truth of plaintiff's allegation regarding the existence and content of the security directive described in plaintiff's Complaint."
But it might not, apparently, in which case one wonders what everybody was doing down the courthouse. Or it might, because "this Court might find the precise content of any alleged security directive to be necessary for resolution of plaintiff's appeal." But "any such directive" can't, according to federal statute be disclosed in open court. So the lawyers want to file materials and their opposing brief under seal. They also propose to file a redacted, unsealed version, so if that happens we can all have fun imagining what the blacked out bits might (or might not) say.
Gilmore is no stranger to airline run-ins. Last year he was thrown off a British Airways flight from San Francisco for refusing to remove a lapel badge reading "Suspected Terrorist." His display of the badge apparently endangered the aircraft's security, according to BA. ®