I have been surprised that I have not seen any discussion of Portal type explosive trace detection vs the Whole Body Imaging scanners. I am talking about the detectors that you step into and then they blow puffs of air onto you and then they try to detect traces of explosive materials from the air. These have been deployed at a few airports (like TPA). Wouldn't these be effective against the type of attack that occurred on Christmas day? Why haven't they been included in the discussion in the news media? They bring up many fewer privacy concerns than WBI.