This is surprising from the liberal 9th. ID check at U.S. airports not unconstitutional - court SAN FRANCISCO (Reuters) - Airlines and the U.S government have the right to keep passengers from boarding planes if they refuse to show personal identification, a U.S. appeals court ruled on Thursday. John Gilmore, co-founder of the Electronic Frontier Foundation, an online civil liberties group, sued after Southwest and United Airlines in 2002 both did not allow him on board their flights when he refused to show any ID. In court filing, he argued that requiring identification from airline passengers was unconstitutional, but a three-judge panel of U.S. 9th Circuit Court of Appeals disagreed. "We hold that neither the identification policy nor its application to Gilmore violated Gilmore's constitutional rights, and therefore we deny the petition," Judge Richard Paez wrote. "The Constitution does not guarantee the right to travel by any particular form of transportation." "He was not threatened with arrest or some other form of punishment; rather he simply was told that unless he complied with the policy, he would not be permitted to board the plane. There was no penalty for noncompliance." The United States has stepped up its scrutiny of identification cards at airports over the past decade, with additional checks added after the Sept. 11, 2001 attacks when hijacked commercial jets flew into the World Trade Center. Roger & Amanda La France