Air travelers, mark your calendar. An activist opposed to the new invasive body scanners in use at airports around the country just designated Wednesday, Nov. 24 as a National Opt-Out Day. He's encouraging airline passengers to decline the TSA's technological strip searches en masse on that day as a protest against the scanners, as well as the new "enhanced pat-downs" inflicted on refuseniks.

"The goal of National Opt-Out Day is to send a message to our lawmakers that we demand change," reads the call to action at OptOutDay.com, set up by Brian Sodegren. "No naked body scanners, no government-approved groping. We have a right to privacy, and buying a plane ticket should not mean that we're guilty until proven innocent."

Some travel writers have expressed concern that the protest, called for the busiest air-travel day of the year, could cause backups and delays for all travelers.

The planned protest taps a growing unease over the full-body scans. Privacy groups such as the Electronic Privacy Information Center are seeking a court order to halt the use of invasive scanners, saying the scanners are illegal and violate passenger privacy.

They also say the government has done little to ensure that images taken by the devices are not saved. The TSA has asserted that the machines cannot store pictures, but security personnel at a courthouse in Florida were found to not only have saved images but shared them among colleagues in order to humiliate one of their co-workers.

Scientists have also expressed concern that radiation from the devices could have long-term health effects on travelers.

Although passengers have the right to opt out of going through a scanner, the Transportation Security Administration recently announced that passengers who opt out of body scanners at airport security checkpoints would be required to undergo an enhanced physical pat-down that would include agents using open hands and fingers to touch and press chest and groin areas of passengers. In the past, agents were instructed to use the backs of their hands for pat-downs.

Sodegren, who declined to be interviewed in the wake of growing publicity about his movement, wrote on the site that, "You should never have to explain to your children, 'Remember that no stranger can touch or see your private area, unless it's a government employee, then it's OK.'"

The U.S. Airline Pilots Association and other pilot groups have urged their members to avoid the scanners and have also condemned the new pat-down policy as humiliating to pilots. They've advised pilots who don't feel comfortable undergoing pat-downs in front of passengers to request they be conducted in a private room. Any pilots who don't feel comfortable after undergoing a pat-down have been encouraged to "call in sick and remove themselves from the trip."

Travel writer Carl Unger expressed concern that the timing of the boycott could affect already frazzled passengers who are trying to reach their Thanksgiving destinations.

"Chaos makes great news, sure, and news makes great exposure for a cause such as this," he wrote at Smarter Travelbut I wonder if throwing a wrench into people's holiday travels is the best way to win hearts and minds."

Homeland Security Secretary Janet Napolitano was set to meet with executives from the travel industry on Friday to discuss concerns that security is having a detrimental effect on travel, according to Reuters.

"We have received hundreds of e-mails and phone calls from travelers vowing to stop flying," Geoff Freeman, an executive vice president of the U.S. Travel Association, told the news agency.