As you read in this space last week, the Transportation Security Administration, and not the Supreme Court, now gets to decide what constitutes an unreasonable search in this country. Jeffrey Rosen, who has made the privacy beat his own, now brings us the backstory of the porn machines, and how Europe's privacy czars spared their citizens the humiliation of this invasive and possibly useless technology:

Eight years ago, officials at Orlando International Airport first began testing the millimeter-wave body scanners that are currently at the center of a national uproar. The designers of the scanners at Pacific Northwest National Laboratory offered U.S. officials a choice: naked machines or blob machines? The same researchers had developed both technologies, and both were equally effective at identifying contraband. But, as their nicknames suggest, the former displays graphic images of the human body, while the latter scrambles the images into a non-humiliating blob.

Since both versions of the scanners promise the same degree of security, any sane attempt to balance privacy and safety would seem to favor the blob machines. And that's what the handful of European airports that have adopted body scanners chose. This is in part due to the efforts of European privacy commissioners, such as Germany's Peter Schaar, who have emphasized the importance of designing body scanners in ways that protect privacy. However, most European airport authorities have declined to adopt body scanners at all, because of the persuasive evidence that they're not effective at detecting low-density illegal material, such as the chemical powder PETN concealed by the so-called underwear bomber last Christmas.


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