OK.
Polygraphs may not be as in vogue today as they were in previous decades. That being said, they're still widely used in certain institutions in society. I'm not talking about Maury, or Dr Phil. For instance, the NSA (National Security Agency) uses polygraphs on its employees.
There's not much that we in the Northeast can do about the NSA using it, naturally. However, there are law enforcement agencies that use polygraphs as well.
linkNow, there seems to be a sizable amount of evidence that polygraphs aren't foolproof, and that seems to be the general consensus among the populace (or at least, this forum.) However, if that's not enough, the American Psychological Association also agrees:
linkSimply put, the polygraph is simply a measure of things like blood pressure, heart rate, and other bodily functions. It isn't a clean-cut way to determine the truth, because isn't being hooked up to a big scary machine likely to taint any responses in question?
Also, there is the matter of teaching individuals how to "combat" or "defend against" polygraph testing. Chad Dixon, a polygraph counselor, was recently sentenced to eight months for teaching countermeasures. There are other instances of people receiving slightly harsher sentences for such a practice, which I can dig up if need be.
Why is this so? If the polygraph is inherently faulty, then why should the Northeast prosecute those who really aren't doing much other than exposing these machines for what they are?