Because you know your phone is tapped
Tele-Data Guard detects surveillance.
The market timing for products like the "Tele-Data Guard" couldn't be better, coming on the heels of the recent spate of spy movies such as The Good Shepherd, Breach and The Company. We can think of no better way to heighten people's sense of paranoia.
Besides, who hasn't had their phones tapped as part of international conspiracies? That's what this device is aimed at detecting (well, maybe not the conspiracy part), by flashing a green light during conversation if someone is eavesdropping on your line, according to Uber-Review. It supposedly works on faxes and modems too.
But why limit your communication protection to land lines? We suggest blocking all forms of intrusion by getting fitted with the proper tin-foil hat.