Many of today’s cell phones can be used as bugs, invading your privacy. The reasons for this can range from snooping and practical jokes to industrial and political espionage. This is usually accomplished in one of two ways:

Phones can be set to ‘silent ring’ and ‘auto answer’, and hidden in some specific location. Later, the perpetrator simply calls the hidden phone, which turns into an instant transmitter. Phones’ embedded programming can be altered to turn them into receivers – effectively turning your own phone into a bug so that someone else can listen in on your conversations. This is theoretical today – I do not believe this has ever actually been done. But as cell phones become “smarter” (more like tiny Windows systems than phones), sooner or later the writers of malicious code may figure out a way to produce a cell phone “virus” that will turn a phone into an illicit transmitter in order to eavesdrop on people. This video, while somewhat humorous, makes a good point.

New article on this topic:

http://www.komotv.com/news/11847636.html

This is yet another example of technology with unintended consequences that is subject to abuse. More here.