Another thing that occurs to me, especially given recent publicity, is how this affects privacy. There are some/many things that are private and which you do not want the government or corporations to know. It is outside criminal actions and therefore none of their business, but if lie detectors become omnipresent, then it will become more and more tempting to use them everywhere to make things "more efficient" and to start everyone and their dog to asking more and more things that are none of their business.