Former presidential candidate Ralph Nader said the body scans and enhanced security pat-downs at US airports are eating away at Americans' freedoms and called the agency that conducts them a "basketcase."

"The TSA is a basketcase, collectively," Nader said at the first US conference on controversial new security measures that are being rolled out at airports around the United States.

These include X-ray scanners that produce a graphic image of a person's naked body, genitalia and all, and body searches including a frisk of the private parts of travelers who refuse to go through the scanners.

Some travelers have complained that the scanners are too revealing, while others, including a pilot, have said they felt violated after being frisked by a Transportation Security Administration (TSA) agent.

Passengers and airline crewmembers have told stories about being asked to remove prosthetic breasts or having their urine-collection bag burst during a pat-down, and parents have said their toddlers were invasively searched by TSA agents.

The TSA security strategy was to have a knee-jerk reaction to failed terror attacks, said Nader.

"You have the shoe bomber, we take off our shoes.

"You have the Christmas bomber headed for Detroit who failed, so now we have these new scanner machines," he said, referring to a young Nigerian who tried unsuccessfully to detonate explosives sewn into his underpants as his US-bound flight was about to land on Christmas Day, 2009.

Next thing American travelers know, they will be subjected to body cavity searches, he said.

"What's happening is, we are incrementally losing our freedoms," Nader said.

That view was shared by most of the other speakers at the conference, which was organized by the Electronic Privacy Information Center and had the double-entendre name "The Stripping of Freedom."

"The TSA wants to use machines to see us naked before we get on an airplane," said Wes Benedict, head of the Libertarian Party.

"But if you don't want to be seen naked, you can get patted down like a criminal and felt up instead," he said, agreeing with Nader that the new security measures "trample on our rights and waste our money."

Congressman Rush Holt said that making everyone go through the scanners goes against a "central tenet of our society and our government, that we do not regard people with suspicion first."

Michael Roberts, a US pilot who last year refused to be patted down by the TSA, said the scanners were another example of the government meddling in Americans' private lives.

He and James Babb, co-founder of a grassroots movement that called for travelers to boycott body scans on the busiest travel day of the year -- the day before Thanksgiving -- called for the TSA to be abolished and for travelers' security to be put in the hands of the free market.

But amid the voices saying that the new security measures were violating Americans' constitutional right to privacy and calling for the TSA's heads, a lone voice came out with a different reason for why the agency should change the way it screens travelers.

Simply put, scanners don't work, said international security expert Edward Luttwak.

In a test conducted in Europe, German prison guards were instructed to sneak explosives past three different scanners, including the full-body X-ray machine currently causing such a furore in the United States, Luttwak, a senior associate at the Center for International and Strategic Studies, said.

"They did it with such ease that the Air Travel Association, IATA, said there is no case for scanners," said Luttwak.

The better solution would be to use data that is available to the travel industry to identify and separate frequent fliers and other travelers who are unlikely to be terrorist wannabes from travelers who, for whatever reason, arouse suspicion. Then, only screen suspect travelers.

"The guy who has traveled 50 times in the last 50 weeks without blowing up an airplane is unlikely to become a terrorist the 51st time," said Luttwak.

This sort of screening method is already used successfully at airports around the world, including in high-risk countries like Israel, Luttwak said.

If the TSA were to switch to it, they would not only save travelers a lot of time and headaches, but would also reduce the security risk that has been created at US departure terminals by long, slow-moving lines of passengers waiting to clear security.