Confiscated cell phones at Broad River Correctional Institution, where the Federal Bureau of Prisons ran a cellphone-jamming experiment in partnership with state corrections officials last week, in 2010. Photo : Meg Kinnard ( AP )

The U.S. Federal Bureau of Prisons tested cellphone-jamming technology at the state-run maximum security Broad River Correctional Institution in Columbia, South Carolina, last week, the Associated Press reported, in what the Verge noted may be a prelude to state prisons gaining more power to keep incarcerated persons out of contact with the outside world.




Jamming is the intentional disruption of radio frequencies to interfere with legitimate communications, and it is generally banned and subject to heavy penalties in the U.S. outside of limited use by federal agencies. According to the AP, Department of Justice officials said the test ran over five days in a housing unit at the prison, with Assistant Attorney General Beth Williams saying that it was the first such joint federal-state test.

South Carolina Corrections Director Bryan Stirling received special deputy federal marshall status. That gave him the authority to carry out a so-called “micro-jamming” exercise, which is supposed to interfere with communications in a very small area, the AP wrote:

Micro-jamming technology was tested last year at a federal prison—where officials said they were able to shut down phone signals inside a prison cell, while devices about 20 feet (6 meters) away worked normally—but a decades-old law says state or local agencies don’t have the authority to jam the public airwaves.


The Federal Bureau of Prisons is free to use jamming technology, though the AP separately reported earlier this month it hasn’t been used outside of limited testing. In both federal and state penal facilities, contraband access to cell phones is common, which prison officials have long alleged they need more tools to address.

Those officials have cited security concerns like contact with outside criminal elements, saying prisoners could deal drugs, engage in organized crime, or order retaliatory hits on law enforcement and prison personnel. Those behind bars have often alleged it has more to do with protecting lucrative arrangements restricting them to expensive, exploitative phone lines run by private contractors that (at local prisons) can run into the dozens of dollars for 15-minute calls.

As the Verge noted, the Federal Communications Commission has previously loosened rules to allow prisons to run managed access systems, which are systems in which facilities partner with mobile companies to set up networks that can only be used by whitelisted devices. Tests of those systems have faced challenges in “fine-tuning the signal, refining the approved devices list, and establishing good working relationships with commercial carriers,” according to the National Institute of Justice, and are also often riddled with “holes” allowing devices to connect to commercial networks. They can also be damaged or deliberately sabotaged (something that would also theoretically be true of a jammer).

Republican Senators Tom Cotton and Lindsey Graham also recently introduced legislation to allow state prisons to use jammers, while similar legislation was proposed in the House. According to the AP, the FCC has also been receptive to concerns raised by prison officials.


However, critics have also warned that allowing state prisons to run cell phone jamming systems would weaken the federal ban on jamming.

As io9 noted all the way back in 2010, there are all kinds of businesses that might have an interest in jamming cellular networks. Some uses may sound innocuous, like preventing cell-phone use movie theaters, but it could be used in search of profit (say, sports venues restricting mobile data in favor of paid wifi access). Police forces in the U.S. have also occasionally interfered with the normal operation of wireless networks to disorient protesters or prevent them from organizing. There’s also the possibility of more widespread jammer use interfering with day-to-day wireless communications.


It’s worth mentioning the U.S. incarcerates more people per capita than any other country in the world, with a recent study finding up to 45 percent of U.S. residents have a family member who has spent at least one night in jail or prison.

North Carolina-based wireless communications expert Ben Levitan told Motherboard last year, “Allowing jamming technology is a very slippery slope, and once that door is opened we can never turn back. I’ve been in this business for 30 years. If someone is advocating for new technology they probably know someone who sells equipment or has a piece themselves.”




“There is money to be made,” Penn State University telecommunications chair and X-Lab founder Sascha Meinrath told Wired. “Prisons are just easy use-test cases for private companies to demonstrate technology because it’s a vulnerable population. As soon as its approved to work there, other venues will be clamoring to roll it out. Then where can we draw the line?”

[Associated Press via the Verge]