But couldn't it be argued that the use of body-scanners functions as a form of strong deterrent for potential plots? If a potential terrorist understands that they will eventually be caught or that the stakes to beat the system are too high, they will look at alternative forms of terrorism simply because the investment to beat airport security is too high.
And to sort of extend my point. We always laugh at CEOs/CTOs when they fail to provision money/resources for security software and security measures in organizations. That, instead of paying for security up-front, they wait until after a disaster to respond with security measures. In this case, by criticizing the spending of scanners as a deterrent to potential plots, are we not playing the part of CEO who complains…
When the cost of security exceeds the cost of what's being protected, the solution need be reconsidered.