Wow, reading this info has been an eye opener.  I'm glad the Employee Polygraph Protection Act exists, but it doesn't go far enough.  In the US, a polygraph can still be used in security companies, armored car companies, and pharmaceutical companies.  The government is also exempt.  

The EPPA should be expanded to cover all those.  Basically, it should be illegal to use a polygraph for anything other than a parlor trick.   This polygraph thing isn't any more reliable than tarot cards, pendulums, or horoscopes.