See related story: Secret ID Law Goes to Court

Electronic Frontier Foundation founder John Gilmore hands a "suspected terrorist" button to a supporter Thursday outside the San Francisco courthouse hearing his legal challenge to a secret airline security rule.
Ryan Singel
John Gilmore says he hasn't flown within the United States since 2002. "When a cop asks you for your ID on the street, you are free to walk away," he said. "If you refuse to show ID at an airport, you can't fly."
Ryan Singel