In a recent Washington Post-ABC News poll, only 32 percent of respondents said they objected to the full-body scans, although 50 percent were opposed to the pat-downs offered as an alternative. That means opponents of the new measures will have to shift their efforts from the airports to the courts.

Although the Supreme Court hasn't evaluated airport screening technology, lower courts have emphasized, as the U.S. Court of Appeals for the 9th Circuit ruled in 2007, that "a particular airport security screening search is constitutionally reasonable provided that it 'is no more extensive nor intensive than necessary, in the light of current technology, to detect the presence of weapons or explosives.' "

In a 2006 opinion for the U.S. Court of Appeals for the 3rd Circuit, then-Judge Samuel Alito stressed that screening procedures must be both "minimally intrusive" and "effective" - in other words, they must be "well-tailored to protect personal privacy," and they must deliver on their promise of discovering serious threats.

As currently used in U.S. airports, the new full-body scanners fail all of Alito's tests. First, as European regulators have recognized, they could be much less intrusive without sacrificing effectiveness. For example, Amsterdam's Schiphol Airport use scanners which employ radio waves with far lower frequencies than those used in common hand-held devices. If the software detects contraband or suspicious material under a passenger's clothing, it projects an outline of that area of the body onto a gender-neutral, blob-like human image, instead of generating a virtually naked image of the passenger. The passenger can then be taken aside for secondary screening.

In the Netherlands, there's another crucial privacy protection: Images captured by the body scanners are neither stored nor transmitted. Unfortunately, the TSA required that the machines deployed in U.S. airports be capable of recording, storing and transmitting images when in "test" mode. The agency promised, after this capability was revealed by a Freedom of Information Act lawsuit filed by the Electronic Privacy Information Center, that the test mode isn't being used in airports. But other agencies have abused the storage capability of the machines. The U.S. Marshals Service admitted in August that it had saved more than 35,000 images from body scanners at the Orlando federal courthouse.

In January, the European Commission's information commissioner criticized the scanners' "privacy-invasive potential" and their unproven effectiveness. And tests have shown that the machines are not good at detecting low-density powder explosives: therefore they wouldn't have stopped the bomber who concealed chemical powder in his underwear last Christmas.

I am not comfortable subjecting myself to either of these search methods and I sure as hell wouldn't allow either of my preteen nieces to be subjected to it. Hopefully the public will insist on change. Time will tell.