Just got some, considering putting one on my carry on.
My great fear: How long till some TSA burro-crat issues a SSI to the crew:
"All cattle/pax with yellow FT tags are Known Troublemakers and Pax with a Negative Attitude to TSA Incompetency. This will not be tolerated.
Automatic secondary and the works for all yellow FT tag holders"
Strip search em, Denno!