Don't forget that there is no real way to validate what level of scanning is being done by the TSA. Example images on placards at the airport only show what the government want normal people and potential terrorists to see. If terrorists knew exactly how much scanning was occurring, they could adapt likewise.

Therefore, it is implausible to expect the TSA to be honest about how high the scanning level is set. In effect, the TSA will feed the general public propaganda to stop the enemy from being more diligent in their stealth.

Nice, eh - considering this was the state of the art 4 years ago:
http://rupture.co.uk/Terminal%204.html