Man Rigs Ingenious — but Illegal — Cellphone Jamming Device on His Car to Stop an Annoying Problem

Watching fellow commuters talk on their cellphones while driving ticked a Florida driver off so much, he decided to take matters into his own hands.

Jason R. Humphreys rigged a signal jammer in his SUV to block distracted drivers from making cellphone calls around his vehicle.

Who hasn't gotten fed up with people talking while driving? A man used these jammers to block distracted drivers from making calls around him. (Image source: WNYW-TV)

His ingenious scheme worked for almost two years, before the Federal Communications Commission tracked him down.

Cellphone signals are blocked with a jamming device that broadcasts on the same frequency (Image source: HowStuffWorks).

Humphreys is now facing a $48,000 FCC fine for using the jammer during his morning and evening commute on Interstate 4 between Seffner and Tampa.

Metro PCS alerted the feds of an issue in April 2013. The cellphone company noticed that its cell tower sites had been experiencing interference during the morning and evening commutes, WNYW-TV reported.

Jamming devices overpower cellphones by transmitting a signal on the same frequency and at a high enough power that the two signals collide and cancel each other out.

But cellphones usually operate on two frequencies: one for listening and one of transmitting, simultaneously. Phones are designed to add power if they experience low-level interference, so the jammer must recognize and match the power increase from the phone.

In a statement, the FCC said they used "sophisticated interference detection techniques" to track down the source of the jamming: Humphrey's blue Toyota Highlander SUV.

"Mr. Humphreys’ jammer operation could and may have had disastrous consequences by precluding the use of cellphones to reach life-saving 911 services provided by police, ambulance and fire departments,” the FCC said.

Federal law prohibits the operation of jamming devices in the United States. While Humphrey's actions may seem harmless enough, had the same signal manipulation techniques had been used by a terrorist, it's easy to see how the danger could quickly escalate.

The FCC considers any radio frequency transmitters that intentionally block, jam or interfere with authorized communications such as cellphone calls, GPS systems, Wi-Fi networks and first-responder communications illegal.

"It is a violation of federal law to market, sell, import or use a signal jammer in the United States and its territories, except in very limited circumstances involving federal law enforcement," the FCC said. "While these devices have been marketed and sold with increasing frequency over the Internet, their use by U.S. consumers is illegal under any circumstances. Unlawful use of signal jammers could result not only in substantial monetary fines, but also imprisonment."

(H/T: WNYW-TV)

—

Follow Elizabeth Kreft (@elizabethakreft) on Twitter.