Oct. 28, 2010 -- Next time you pass through security in some airports around the country, you may face a difficult dilemma: Would you rather have a revealing, full body scan or what some are calling an X-rated pat down?
Some passengers opt out of the full-body scan, concerned about the low doses of radiation emitted by the high-tech body scanners that are being put in place in many terminals. The machines also are able to see beneath clothes, creating a photo-realistic picture of the passenger's body.
But for those who refuse the scan, the alternative pat down is about to get equally thorough.
Watch "World News with Diane Sawyer" for more on this story tonight on ABC.
Starting Friday, the TSA is changing its pat-down procedure. TSA officers used to pat down passengers with the backs of their hands, but now they'll use the fronts of their hands to search more than ever before, in some cases touching body parts that once were off limits.
A security expert who demonstrated the new procedure on a mannequin for ABC News explained the changes.
"You go down the body and up to the breast portion," said Charles Slepian of the Foreseeable Risk Analysis Center. "If it's a female passenger, you're going to see if there's anything in the bra."
The new pat-down protocol could be used at any of the nation's 450 airports on passengers who require additional screening.
Experts say there's a solid reason for the more invasive examinations: It's possible to slip a gun through the existing pat down, and there's even concealment clothing for sale to make it easier.
Search Won't Catch Everything
Critics, though, point out that even a more invasive search won't catch everything. For instance, would it catch someone like the underwear bomber? Does it catch explosives?
"Not likely," Slepian said. "The underwear bomber had powder in his underpants. You really don't know if there is an explosive there."
Others are critical of the new methods for different reasons, saying that the pat down and x-ray infringe on passengers' rights.
"It's intrusive, it's unnecessary and it's too much," said Kate Hinni, the executive director of FlyersRights.org.
Even some pilots apparently agree. A Memphis pilot who recently refused the pat down and the body scan was barred from flying entirely.
"They subjected me to multiple layers of absurdity," said Michael Roberts on ABC News' "Good Morning America." "In the current world we live in, it doesn't require stripping away our rights and liberties."
British Airways President Criticizes Security Checks
Even the president of British Airways criticized U.S. security measures recently, calling the checks "completely redundant," and adding, "Airlines shouldn't kowtow to the Americans."
Still, the TSA defended its new policy in a statement to ABC News, saying its goal is simply to "stay ahead of evolving threats."
"Pat downs are designed to address potentially dangerous items like improvised explosive devices and their components, concealed on the body," the organization wrote.