How criminals—or even people just looking for some illegal peace and quiet—could use jammers to bring down parts of America’s infrastructure.

It was a quiet day in church. Except for the small device in Jim’s pocket, which was vibrating like crazy. That device was a jammer detector, and it told Jim (not his real name) that something was amiss. After the sermon, the vibrating stopped.

Jim approached the priest and asked him if he was using a cell phone jammer, according to Professor Charles Curry, with Chronos Technology, a company that makes jammer detectors.

Yes, the priest said, proudly showing his jammer.

“Look at it. Nobody interrupts my sermons any more!” the priest exclaimed.


God might approve of jammers in church, but the federal government does not. The Federal Communications Commission says it is illegal to sell or use jammers in the U.S.

Still, experts in the area of jammers and protection from jammers say the number of these illegal devices coming into the U.S. is growing.

“You can buy them on a next-day DHL package service form China for $50,” Curry told Archer News.


It’s not just about preventing your neighbor from making a call to 911 in an emergency, but potentially shutting down infrastructure that you depend on to live and work, experts say. They worry that terrorists or other adversaries will use this easy and inexpensive form of attack.

“We know that terrorists have been arrested with GPS [Global Positioning System] jamming devices in their possession,” said Dana Goward, president of the Resilient Navigation and Timing Foundation in Washington, D.C.

“If you parked next to a cell site, you’d probably cause that cell site to fail,” said Curry.

“A three-watt jammer could probably knock out a couple of blocks in a city, or maybe more,” he added. “You could stop the whole of Wall Street with a reasonably powerful jammer.”

A digital ‘stay off my lawn’

Just last week, a 63-year-old Chicago man went to court over his brazen jamming of cell phone calls on a commuter train, reported The Chicago Tribune.

“Everyone was looking at their phones like—what the hell?” one rider said, according to the Tribune.

Another rider told the paper, “I think he liked the feeling of being in control of the car. It’s kind of a digital ‘stay off my lawn, you young people with your cellphones.'”

The jammer user’s lawyer said his client, Dennis Nicholl, who had been to court for the same thing in 2009, according to the Tribune, just wanted peace and quiet.

Crime & punishment

Nicholl was first charged with felony unlawful interference with a public utility, but it was later changed to misdemeanor tampering with communication services, the Tribune reported. 

Some people called Nicholl their “hero” for silencing loud cell phone conversations. Others, like a rider on the train who took a picture of the accountant with his five-antenna device, said it was troubling “in terms of security and terrorist threats in any major city,” according to CBS News.

The judge sentenced Nicholl to a diversion program where he can attend counseling sessions instead of going to jail, reported the Chicago Tribune, and the misdemeanor charges against him could be dropped if he successfully finishes the program this summer.

Serious consequences

Some say there should be more severe punishments for people using jammers, because of the damage they can do.

The big problem—jammers can block GPS signals, too, experts say. Some jammers are just for zapping cell calls, some are just for GPS blocking, and some are for both. But Goward and Curry say all three can potentially stop GPS in its tracks.

“Anything that uses GPS technology for either positional information or timing information is vulnerable,” said Curry.

That could include building sites, ships moving in and out of harbor, civil engineering, parts of the power grid, broadcasting, telecommunications sites and more, he said.

“Dependence on GPS is getting greater and greater all the time,” said Goward.

“We had an East Coast port shut down for seven hours,” he said, “Because one of the trucks coming to pick up a container had a jammer in it. So, all of the cranes were lost. Everything sat idle for seven hours.”

Deadly consequences?

It is not just money, but potentially lives lost as well, some say.

Curry described an incident in 2012 where a man driving a company vehicle and using a GPS jammer to keep his boss from tracking him accidentally killed GPS signals being used for an experimental landing system at the Newark Liberty airport.

“Very luckily, it was only in trial,” said Curry. “But if you would imagine a plane coming in using GPS…”

The FCC fined the man almost $32,000, saying jammers are unsafe.

“They may also disrupt critical emergency communications between first responders, such as public safety, law enforcement, emergency medical, and emergency response personnel,” the FCC said in a public announcement. “Similarly, jammers can endanger life and property by preventing individuals from making

9-1-1 or other emergency calls or disrupting communications essential to aviation and marine safety.”

Who is using jammers?

From time to time, you hear about people trying to use jammers allegedly for the greater good, like a Florida teacher who used the device to keep kids from using cell phones in class.

He ended up blowing out cell signals around the school, according to WTSP in the Tampa area, and the district suspended him for five days.

Then there was the man who used a jammer on the highway in Florida to keep other people from talking on their cell phones while driving, according to the FCC. The agency said his jamming caused problems with cell towers in the area during the morning and evening commute for up to two years, and fined him $48,000 in 2014.

“Your average person will say, ‘I had no idea I could cause damage to other aspects of critical infrastructure,’” said Curry.

Covering their tracks

However, many users are employing the jammers for subterfuge, according to experts.

The devices may be a “favorite tool for organized crime,” said Goward, because criminals can use them to block GPS trackers on expensive cars and cargo shipments, such as pharmaceuticals.

Curry’s research showed a criminal gang used GPS jammers to steal about 150 Mercedes sprinter vans from the Heathrow Airport area in London in 2012.

“A lot of high-value cargo has a GPS tracker somewhere down inside of it,” said Goward. “They jam the GPS until they get the cargo off some place away and safe and dig down inside of it and disable the tracker.”

Keep on truckin’

Truck drivers also appear to be frequent jammer-users, said Curry and Goward. The drivers may jam GPS so employers or authorities won’t know they are working more hours than allowed, or using company vehicles for other loads.

Research showed that jammer use is strong on some of Britain’s roads on weekdays, and drops dramatically on the weekends and holidays, according to Curry.

Other research showed about one of four trucks in the port area of Portland, Oregon had a GPS jammer on board and in operation, said Goward.

Other attempts to use GPS to evade detection include taxi drivers trying to keep from giving a percentage of a fare to the taxi company, drivers trying to escape toll stations, and criminals looking for ways to jam out signals from ankle tracking devices that send GPS coordinates.

“People don’t like being tracked,” said Curry.

Banning jammers

Craigslist and Amazon have banned the sale of jammers. But sites still pop up on the Internet offering the devices for sale.

A company called Jammerfun put out a press release last week about its cell phone jammer, saying it is a “good choice” for people who want silence and safety.

“In order to avoid living under the condition of hustles and bustles, we have to take actions to protect ourselves from all kinds of noise,” Jammerfun’s release said. “And we find that signal jammers devices played an indispensable role in our daily life and also have become the hot list of popular electronic digital products in recent years.”

The company also claimed their jammer only works for about 30 to 45 feet. However, experts say that jammers can actually reach much further than that, and may kill GPS signals, too, even if the ads claim the devices will only stop cell signals.

Jamming the jammers?

The FCC has patrolled craigslist for jammer sellers, and has cracked down a number of times. The agency has also investigated and fined a number of people for using jammers. 

Goward’s group wants to make laws tougher for people using the devices that blow out GPS, including making it a misdemeanor to own a jammer, a felony to use one, and creating a national system to detect jamming and stop the jammers.

The heavier laws could “reflect the possible consequences of this bad behavior,” said Goward.

But the group also wants more—to protect the U.S. from terrorist attacks or nation-state jamming.

South Korea claims North Korea has used jammers on South Korea for years, affecting 1,400 South Korean ships and planes.

Back-up plan

The Resilient Navigation and Timing Foundation is pushing for a secondary system to supplement GPS, called eLORAN. They say eLORAN would provide an alternative way of communicating, navigating and running infrastructure if terrorists knock out GPS, or if there is a technical problem with satellites.

The Department of Homeland Security concluded in a formerly-classified 2011 report that was recently made public that “the widespread and growing use of GPS, coupled with threat actors possessing technologies that can disrupt GPS now and in the future, pose a long term threat that cannot be ignored.”

The report said creating a system of sensors to ferret out jamming could help, along with hardening security on GPS equipment and putting into place a back-up system, in case GPS is disrupted.

As for the guy in Chicago guy who apparently wanted people to “get off his digital lawn,” so to speak?

“I think he’s so scared out of his mind that this happened and he’s facing trouble at his job because of it, so I don’t think this will ever happen again,” his attorney said in The Chicago Tribune. “He just wants to go hide.”