In our law enforcement training classes we teach that suspects often exhibit behavior consistent with counter-surveillance techniques or technical surveillance countermeasures, such as using debuggers to sweep for trackers or electronic eavesdropping devices. This being only one of many counter-surveillance techniques, but one we must prepare for during surveillance.
On the Discovery Channel’s Moonshiner’s series, we see this in action. This video will turn right side up when started. 🙂