CBS's Sunday Morning - Lying About Lying

Today, CBS's Sunday Morning opened with a segment on lying, entertaining but not particularly informative or worthy of comment.

What made me angry, however, was the use of a lie detector - a device that has absolutely no scientific basis. We don't know if it can detect lies at all or, if it can detect them, how often it can, or how often it misidentifies as a lie something that is the truth (or vice versa). Then the "expert" stated that he didn't even need the machine: he could tell if somebody was lying by listening to the voice. Proof? None, of course.

CBS would no doubt say that lie detectors are used by businesses and government agencies around the world, so there is no reason why it shouldn't use one. But, surely, there was no need to promote the device. The segment would have been just as interesting or boring, depending on one's perspective, without including it at all. Why not choose the "at least, do no harm" option?

How many people in the world have lost a job, not gotten a job, or been jailed because of a machine that is about as scientific as a Ouija Board? And why do so many people believe these devices actually work?