Great, not only can you be arrested for suspicion of terrorism, in the not too distant future you can be arrested for sweating suspiciously. In suspicion of suspicion of terrorism they should call it.

Confounders of a polygraph?

? Person is convinced of the lie either by mental disease, hypnosis, amnesia or distorted point of view. It can only help identify when someone is deliberately lying.

? Anxiety and stress may make someone scaried to answer any question and paranoid of possible implications of the questions posed. They may answer trufull but they can still react similar to another persons lie.

? Many stories or conspiracies about special military or esponage training to beat polygraphs and withstand interogations.

The United States National Academy of Sciences says in "The Polygraph and Lie Detection," (NAS Press, 2003, ISBN: 0309084369) that polygraphs have a very high rate of false positives and susceptibility to countermeasures, and most of all, are too easily manipulated (often unconsciously) by the operator. The Office of Technology Assessment, United States Congress in “Scientific Validity of Polygraph Testing: A Research Review and Evaluation” (ISBN: 1410210707) said the same things.

In other words, the official scientific body of the US Government, the NAS, as well as the US Congress’ OTA, says polygraphs don’t work. Of course, we all know how the US Government’s policies are science driven…

Anyone can be trained to fool the polygraph in just five minutes. All of the spies caught in the US such as Robert Hanssen & Aldrich Ames passed multiple polygraph tests during their careers, and were first detected through other means. No spy has ever been caught in the US based on a polygraph examination.