CHICAGO -- Travelers dismayed by airport body scans are headed to airports Wednesday with the makings of any good protest: handmade fliers, eye-catching placards, slogan-bearing T-shirts -- and Scottish kilts.

The loosely organized effort dubbed National Opt-Out Day hopes to highlight what some call unnecessarily intrusive security screenings. Others fear it will merely snarl pre-Thanksgiving airline operations on one of the busiest travel days of the year.

Robert Shofkom wasn't worried about delayed flights, maybe just strong breezes.

The 43-year-old from Georgetown, Texas, said he planned for weeks to wear a traditional kilt -- sans skivvies -- to display his outrage over body scanners and aggressive pat-downs while catching his Wednesday flight out of Austin.

"If you give them an inch, they won't just take in inch. Pretty soon you're getting scanned to get into a football game," the IT specialist said.

Shofkom was momentarily disheartened when his wife informed him Tuesday that the Austin airport doesn't yet have body scans. But he decided to wear the kilt anyway, a show of solidarity with fellow protesters who have taken to Facebook and other websites to tout plans for similarly revealing travel outfits.

One Internet-based protest group called We Won't Fly said hundreds of activists would go to 27 U.S. airports Wednesday to pass out fliers with messages such as "You have the right to say, `No radiation strip search! No groping of genitals!' Say, `I opt out."'

"If 99 percent of people normally agree to go through scanners, we hope that falls to 95 percent," said one organizer, George Donnelly, 39. "That would make it a success."

If enough people opt for a pat-down rather than a body scan, security-line delays could quickly cascade.

More than 40 million people plan to travel over the Thanksgiving holiday, according to AAA, with just more than 1.6 million flying -- a 3.5 percent increase from last year. Body scans for passengers chosen at random take as little as 10 seconds. New pat-down procedures, which involve a security worker touching travelers' crotch and chest areas, can take 4 minutes or longer.

Several travel companies, including Travelocity, planned on-site monitoring at airports Wednesday to try to gauge where and why delays happen. But with a vicious storm already hindering travel in Western states Tuesday, determining if weather or protests are behind delays across the vastly interconnected air travel system could be nearly impossible.

The full-body scanners show a traveler's physical contours on a computer in a private room removed from security checkpoints. But critics say they amount to virtual strip searches.

About 70 airports nationwide have more than 400 of the refrigerator-sized imaging units. Only around 20 percent of travelers are asked to go through them, but passengers cannot opt out of both the scan and the pat-down once they have been randomly selected for the enhanced searches.

Officials say the procedures are necessary to ward off terror attacks like the attempted bombing of a Detroit-bound plane last Christmas by a Nigerian man who stashed explosives in his underwear.

At a main checkpoint in Atlanta on Tuesday, a few passengers asked to step through a scanner grimaced before walking through, while others seemed more bemused than annoyed.

Out of 30 asked to go through during a half-hour period, just two opted for a pat-down. Karen Keebler, 54, of Atlanta said later that her main concern was the low-level radiation. The TSA says the scans emit very low radiation and aren't a health risk.

"I just think the less radiation the better, and if you can opt out, you need to," she said.

Wednesday's planned protest is the brainchild of Brian Sodergren of Ashburn, Va., who constructed a one-page website early this month urging people to decline scans.

But public interest boomed after an Oceanside, Calif., man named John Tyner resisted a scan and groin check at the San Diego airport with the words, "If you touch my junk, I'll have you arrested." A cell-phone video of the incident went viral.

Tyner's words became famous, spawning online sales of T-shirts, bumper stickers and even underwear emblazoned with the words, "Don't Touch My Junk!" A Google search of the phrase on Tuesday registered 4.2 million hits.

Saturday Night Live jumped on the controversy last weekend, with a minute-long skit equating the TSA with a dating service. The skit ends: "It's our business to touch yours."

Pilots and flight attendants also had complained about being subject to body scans and pat-downs. On Friday, the TSA said pilots could avoid the more intense screening. TSA spokesman Nick Kimball confirmed the same for flight attendants Tuesday.

Both groups must show photo ID and go through metal detectors. If that sets off an alarm, they may still get a pat-down in some cases, he said.

Publicity or no, some predicted little fallout from the planned protest, with many travelers at airports Tuesday deriding the effort and saying the stepped-up security measures made them feel safer.

"I think there ought to be two flights," said Jacksonville, Fla., native Marc Gruber, 53, who was at the Hartsfield-Jackson Atlanta International airport. "One for people who want to be scanned and one for people who don't want to be scanned."