There have been a few things obtained from FOIA that explain what they have done thus far. Not all cellphones have the capability, but a great deal do. The feds wanted to bug a few BG so they basically uploaded some of their own written software onto the perps cell phone. Then as the person walks around or does whatever, the cell phone microphone remains activated and the phone transmits the data like a normal phone call. Of course there is a bit of adjustments in audio, etc. This has been capable on Land lines for a great deal of time. However, it does not work on phones usually unless they are modified in house. With todays technology, the feds can listen through your cell phone while the power is off, they can track where you go, they can monitor your communications. In some telephone exchange and wireless communication facilities, whole floors are dedicated just to the government for this. Its a hazard of the techno world we live in. Just as it is when we e-mail and write on forums. They are on here and watching by the way. Get yourself a faraday cage cell phone pocket and protect yourself just as virus software or a firewall on your computer!!!
They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.
---Benjamin Franklin, Historical Review of Pennsylvania, 1759.