Anti-jamming advocates insist the jamming signals will expand past the desired limits and deny service to lawful users who happen to be nearby, or are far away but in the range of an unobstructed signal. Also a matter of concern is the opportunity for this technology to infiltrate into the regular community, once Pandora's Box is open. Theaters, auditoriums, and churches urge those in attendance to turn off their cell phones, but many do not. Hotels would prefer their guests use their room phones for calls, so they can collect the significant surcharge they impose. Would they "encourage" this by making cell phone calls more difficult to complete?
Another aspect of the jamming debate comes from those who believe cell phone detection is a better way to go. Some federal prisons use an ITT product called Cell Hound to notify staff when cell phones are in use, and to pinpoint their location. This gives staff the opportunity to locate the phone and whoever is using it. By identifying the phone, investigators can then determine who is calling or being called, and when. They can also get the cell service provider for that phone to shut it down, making it useless.
This could provide an important source of intelligence, but it's an imperfect solution. Walls, bars, and even furniture can distort the signal path, distorting the location data. And cell phone providers, as most of us have come to know, are not always quick to act when customers or anyone else makes requests of them.
Signal detection works only when the cell phone is broadcasting. The signal is cut by turning the phone off or removing the battery. A GSM phone excluded from the network can be revived by inserting a new SIM card, which is the size of a postage stamp.
No one knows whether jamming, detection, or better methods of screening out contraband will work best to defeat inmate cell phone use. Whichever method we use, it's a matter of time before inmate ingenuity produces a new way to evade the rules and frustrate correctional staff.