"Federal officials gathered the information from the customer records of two men who were under criminal investigation for purportedly teaching people how to pass lie detector tests."
What? How is that illegal?
What? How is that illegal?
The physiological measurements may be inadmissible to the courts, but if you happen to confess to a crime during the (thoroughly unpleasant) interrogation then that is perfectly admissible. This key point here is why LEOs are so adamant about subjecting their prisoners to polygraph examinations.
Over 95% of Federal court cases end as a result of a plea bargain, despite the plea bargain being offered under threat of lifetime imprisonment and death.
The public should not fear the machines, and the public, knowing that the machines cannot be used to make them seem innocent, should never consent to being hooked up to one.