“Next time you go through airport security, do your best to avoid yawning, whistling, or complaining too much: Any of those behaviors could make you look like a terrorist in the eyes of a Transportation Security Administration screening agent, according to newly disclosed government documents.”
More details on this program, which has no scientific basis whatsoever, at infowars.com
Here are the 92 things that could make you a terrorist:
http://www.documentcloud.org/documents/1695316-spot-referral-report.html#document/p1