Lie great number of lies, depending on how the political wind blows." The question of whether lies can reliably be detected through nonverbal means is a subject of some controversy. Polygraph "lie detector" machines measure the physiological stress a subject endures in a number of measures while he/she gives statements or answers questions. Spikes in stress are purported to indicate lying. The accuracy of this method is widely disputed, and in several well-known cases it was proven to have been deceived. Nonetheless, it remains in use in many areas, primarily as a method for eliciting confessions or employment screening. Polygraph results
Radar detector detector VG-2 Interceptor was the first device developed for this purpose, although more current technology such as the Spectre III (Stalcar in Australia) is now available. This form of "electronic warfare" cuts both ways and since detector-detectors use a similar superheterodyne receiver, many early "stealth" radar detectors were equipped with a radar-detector-detector-detector circuit, which shuts down the main radar receiver when the detector-detector's signal is detected, thus preventing detection by such equipment. In the early 1990s, BEL-Tronics, Inc. of Ontario, Canada (where radar detector use is prohibited) found that the local oscillator frequency of the detector could be altered to be