If this were a replacement to the current backscatter scanners, this would be more interesting. Since it doesn't seem like this would catch knives or other non-

If this were a replacement to the current backscatter scanners, this would be more interesting. Since it doesn't seem like this would catch knives or other non-chemical weapons, this seems like yet another step at the airport that won't provide very much additional security and could provide a lot of false positives, as already mentioned.