A new Transportation Security Agency (TSA) policy will block passengers from flying if they do not have proper ID, but only if they exhibit defiance. Passengers who merely forgot to bring ID will still be permitted to fly, but will be subjected to a physical screening and enhanced baggage screening.

"Passengers that willfully refuse to provide identification at security checkpoint will be denied access to the secure area of airports. This change will apply exclusively to individuals that simply refuse to provide any identification or assist transportation security officers in ascertaining their identity," TSA said in a policy statement. "This new procedure will not affect passengers that may have misplaced, lost or otherwise do not have ID but are cooperative with officers."

Prior to enforcement of this policy, passengers without ID were still permitted to fly after undergoing the more invasive screening regardless of their attitude or their reason for not showing ID.

Security researcher Chris Soghoian sharply criticized the policy and argues that it fails to resolve properly the concerns he raised in a 2007 research paper which revealed that passengers without ID could circumvent no-fly list restrictions. It will merely punish activists, he says, without improving security.

"With hundreds of millions of dollars having already been spent on the various no-fly lists, it is at least interesting to see that someone at TSA is now spending time on fixing the loopholes in the system. The most glaring of this has long been the fact that passengers can refuse to show (or claim to have forgotten) their ID," Soghoian wrote in a blog entry. "TSA's new rule, while perhaps motivated by a desire to beef up security, is significantly flawed. Terrorists will lie, and claim to have lost their ID—while law-abiding citizens wishing to assert their rights will be hassled, and refused flight."

Soghoian, whose house was raided by the FBI in 2006 after he published a proof-of-concept web application for making forged airline boarding passes, has long been a vocal critic of the TSA's practices. He made headlines earlier this year when he disclosed security vulnerabilities that he discovered in TSA's traveler redress web site. His report sparked a Senate investigation which also uncovered disturbing irregularities in the process used by TSA to award the contract for the site.

This isn't the first time that TSA ID policies have faced criticism and scrutiny. The previous policy was challenged in court by Electronic Frontier Foundation cofounder John Gilmore. At the time, the court supported the policy of allowing passengers to fly without ID if they underwent the full screening.

TSA claims that the function of the new policy is to "enhance the agency's risk-based focus on people, not things," but the entire approach lends strength to the arguments made by critics who say that the TSA peddles security theater rather than legitimate security.