[blincoln]

No one took him seriously because "I always have a radio on. It keeps the lasers out." is a textbook example of the kind of thing someone experiencing paranoid psychosis will say.

i.e. there are certainly listening devices that operate based on bouncing a laser off of a window[1] (or some other object), but his use of a quasi-magical protective measure (radios allegedly protecting against lasers) - in addition to the other behaviour mentioned - strongly implies that he was in need of psychiatric care, as opposed to being under surveillance.

FWIW, I've met multiple people with paranoid psychoses of one sort or another, and all of them have incorporated elements of real-world technology into their delusions.

[1] e.g. http://www.lucidscience.com/pro-laser%20spy%20device-1.aspx

[totalZero]

Is he wrong? Adding noise from a radio or TV in the room may be an effective way to obfuscate attempts to use laser reflection surveillance on a window or other diaphragm. Both the device and the person speaking will cause the laser to jitter as the window vibrates.