You be the judge. From the NYT's Room for Debate feature:
While we may view body scanners as an invasion or privacy, they are a necessary evil. That said, I believe that the mass roll-out of body scanners is a total waste of money. First of all, the body scanners based on millimeter wave and backscatter X-ray technology can only see beneath the clothing but cannot see through the body. Customs authorities around the globe are purchasing transmission X-ray systems which can detect internal concealments. Drug traffickers transport their illicit cargo through internal carries, so it is only a matter of time before the aviation industry is targeted in such a manner. -- Philip Baum, managing director of Green Light Limited, an aviation security training and consultancy company.
There is not a single aviation-security measure that can respond to all potential threats. Therefore, if we jettisoned a given measure as soon as we identified some way it can be evaded, there would be no security measures at all. Moreover, there is nothing wrong with acting in retrospect to close a security loophole that nearly caused a disaster and could well do so if exploited even one time. The more options we take "off the table" from the terrorists, the more they are driven to more desperate plots that are less likely to succeed. -- Arnold Barnett worked on aviation security for the Federal Aviation Administration, the Transportation Security Administration.
Exactly two things have made airplane travel safer since 9/11: reinforcing the cockpit door, and convincing passengers they need to fight back. Everything else has been a waste of money. Add screening of checked bags and airport workers and we're done. Take all the rest of the money and spend it on investigation and intelligence. -- Bruce Schneier is a security technologist and author of several books on computer security.
Well, it's pretty clear that the government isn't going to pull back on the security checks, whether or not the they do any good. The exercise has become a kind of security blanket for airline passengers, and if any of these machines were to be taken away, there would be an uproar so huge that it would make the current pat-down debate seem like a trifle (which it really is).