Because they are unreliable. Lots of people think lie detectors are accurate, including some companies and agencies that use them in recruitment. That doesn't change the facts.
I suspect that most agencies and companies know that they don't work very well, but figure they are probably still useful for intimidating a certain percentage of people into telling the truth.
Hi kwhilborn, The discontinuation of the polygraph was valid as the test can be passed by consummate liars (false negatives) or can be masked by medical conditions (false positives). If you really 'believe' something to that extent then you would most likely pass a polygraph, just as if you were a very good liar, so that's another good reason for discontinuation.
kwhilborn, the show says something like 'all the cases are real and all the sentences are real' they do not actually say that they are not reenactments of real cases with real sentences that were originally tried and sentenced in another court.
Exactly, everything is fake...all of it, even my sentence, not that my own assessment of it has made it any better.
Misleading and dissembling is the 22nd out of 28 different types of lies identified in the wiki. http://en.wikipedia.org/wiki/Lie
Hmm get really fit so your heart rate will go down. Or the greatest way to counter a lie detector test would be, is to simply demonstrate saying "I'm not saying anything" while your pulse is elevated (your scared). Then the results are deemed unreliable.