Known by their opponents as "digital strip search" machines, the full-body scanners use one of two technologies—millimeter wave sensors or backscatter x-rays—to see through clothing, producing ghostly images of naked passengers. Yet critics say that these, too, are highly fallible, and are incapable of revealing explosives hidden in body cavities—an age-old method for smuggling contraband. If that’s the case, a terrorist could hide the entire bomb works within his or her body, and breeze through the virtual strip search undetected. Yesterday, the London Independent reported on "authoritative claims that officials at the [UK] Department for Transport and the Home Office have already tested the scanners and were not persuaded that they would work comprehensively against terrorist threats to aviation." A British defense-research firm reportedly found the machines unreliable in detecting "low-density" materials like plastics, chemicals, and liquids—precisely what the underwear bomber had stuffed in his briefs. 

Yet the rush toward full-body scans already seems unstoppable. They were mandated today as part of the "enhanced" screening for travelers from selected countries, and hundreds of the machines are already on order, at a cost of about $150,000 apiece. Within days of the bombing attempt, Reuters was reporting that the "greater U.S. government shift toward using the high-tech devices could create a boom for makers of security imaging products, and it has already created a speculative spike in share prices in some companies."

Which brings us to the money shot. The body scanner is sure to get a go-ahead because of the illustrious personages hawking them. Chief among them is former DHS secretary Michael Chertoff, who now heads the Chertoff Group, which represents one of the leading manufacturers of whole-body-imaging machines, Rapiscan Systems. For days after the attack, Chertoff made the rounds on the media promoting the scanners, calling the bombing attempt "a very vivid lesson in the value of that machinery"—all without disclosing his relationship to Rapiscan. According to the Washington Post:

Chertoff’s advocacy for the technology dates back to his time in the Bush administration. In 2005, Homeland Security ordered the government’s first batch of the scanners—five from California-based Rapiscan Systems.

Today, 40 body scanners are in use at 19 U.S. airports. The number is expected to skyrocket at least in part because of the Christmas Day incident. The Transportation Security Administration this week said it will order 300 more machines.

In the summer, TSA purchased 150 machines from Rapiscan with $25 million in American Recovery and Reinvestment Act funds.

The Washington Examiner last week ran down an entire list of all the former Washington politicians and staff members who are now part of what it calls the "full-body scanner lobby": 

One manufacturer, according to the Cleveland Plain Dealer, is American Science & Engineering, Inc. AS&E has retained the K Street firm Wexler & Walker to lobby for "federal deployment of security technology by DHS and DOD." Individual lobbyists on this account include former TSA deputy administration Tom Blank, who also worked under House Speaker Newt Gingrich.

Chad Wolf—former assistant administrator for policy at TSA, and a former aide to Kay Bailey Hutchison, R-Tex., a top Senate appropriator and the ranking Republican on the transportation committee—is also lobbying on AS&E’s behalf.

Smiths Detection, another screening manufacturer, employs top transportation lobbying firm Van Scoyoc Associates, including Kevin Patrick Kelly, a former top staffer to Sen. Barbara Mikulski, D-Md., who sits on the Homeland Security Appropriations subcommittee. Smiths also retains former congresswoman Helen Delich Bentley, R-Md.

Former Sen. Al D’Amato, R-N.Y., represents L3 Systems, about which Bloomberg wrote today: "L-3 has ‘developed a more sophisticated system that could prevent smuggling of almost anything on the body,’ said Howard Rubel, an analyst at Jefferies & Co., who has a ‘hold’ rating on the stock."

In forecasting the fate of the full-body scanners, we can turn to recent history, which saw the rapid rise—and decline—of the previous "miracle" screening technology. In the years following 9/11, dozens of explosive trace portals (ETPs) were installed in airports across the country, at a cost of about $160,000 each. These "puffer" machines—so called because they blow air on passengers to dislodge explosive particles—were once celebrated as the "no-touch pat down." But in a Denver test by CBS in 2007, a network employee was sprayed with explosives and then walked through the airport’s three puffers without any trouble. The machines also set off false alarms, and they frequently broke down, leading to sky-high maintenance costs.

After spending more than $30 million on the puffer machines—most of them purchased from GE—the TSA announced earlier this year that it was suspending their use. Only about 25 percent of the machines were ever even deployed at US airports. A report last month from the Government Accountability Office found that the TSA had not adequately tested the puffers before buying them.

What will happen if the full-body scanner goes the way of the puffer? Well, there’s always the next generation of security equipment: the Body Orifice Security Scanner, or BOSS chair. This contraption, which has an uncomfortable resemblance to an electric chair, is used in prisons, mostly in the UK, for tracing cell phones, shivs, and other dangerous contraband that’s been swallowed or inserted into body cavities by inmates. So far, it only detects metal, but you never know.

Give me a friendly German Shepherd any day.

Editor's Note: For a different take on body scanners, check out Kevin Drum's post on the subject.