Disclaimer: The photos shown or depicted at the bottom of this paper were provided to me by others or are photos of devices I had built many years ago when it was legal.
The same technology that has led to the current popularity of cellular telephones has also made cellular telephone systems all the more susceptible to unauthorized interception.
Background A comprehensive review of Corporate TSCM program conducted with emphasis upon the following points:
Due to their greater susceptibility to a variety of attacks, telephones probably pose the greatest single threat to audio security. Look around and you see them everywhere, with a growing number of attachments.
Protecting one's information against the threat of technical interception, or eavesdropping, is complicated by the variety of techniques which the eavesdropper has at his disposal. If he is determined to intercept the information, he may employ any or all combinations of threat techniques.