Well, I know from me reading here on FT that TSA routinely runs its grimy blue gloves through people's hair, and that dense hairdos will sometimes alarm the AIT scanners, so the fact that it happened is not a big shock to me, though it's probably a shock to many people who have never seen it happen and don't read FT.
However, just because I'm not surprised doesn't mean I'm also not outraged and disgusted by the idea that a government agent can assert so much authority over your person that they can run their fingers through your hair to look for prohibited items. It's a ridiculous, bogus, BS threat - the biggest hairdos I've ever seen couldn't possibly hold enough of any kind of explosive to do any appreciable damage to a plane. Searching someones hair is, as the entire AIT/full-body rubdown debacle is, an egregious personal violation that flies directly in the face of both the 4th Amendment and the landmark court decisions which defined the administrative search doctrine.
I'm also saddened by Gabrielle's willingness to laugh it all off as a lark. Unfortunately, so many people live in the "Post 9/11 World" (which is akin to living in Cool World or Sin City or Oz) that they simply have no conception of how much freedom we've lost in the last decade.