Jammers have lawful consumer use

　　That GPS tracking devices have been jammed by criminals engaged in nefarious activity including cargo theft and illicit shipping of goods.

　　In a test conducted by a federal law enforcement agency, GPS jamming devices were determined to be effective to approximately 65 feet. A large GPS jammer can disrupt any tracking device or receiver within a radius of several hundred yards.

　　GPS jammers are transmitters that block tracking devices from acquiring GPS broadcast signals by transmitting electromagnetic interferencea (noise) on the same frequencyb . They come in many shapes and sizes, with varying capabilities. Plugged into a standard cigarette lighter jack, a small jammer operating in the vehicle will disrupt GPS logging or GPS tracking systems for a radius of up to five yards.

　　Mid-sized and larger jammers typically block a combination of GPS, cellphone, Wi-Fi, and other signals and thus also prevent the tracker from wirelessly reporting any location or status data.

　　The use of the GPS jammers was an apparent attempt by thieves to thwart the tracking of the shipping containers.

　　Cargo thieves in North Florida used GPS jammers with a stolen refrigerated trailer containing a temperature controlled shipment, according. In this incident, the hauling tractors were swapped out by the cargo thieves. The Miami based suspects were ultimately stopped and apprehended by the Florida Highway Patrol in mid-Florida on a routine vehicle stop; the shipment was recovered intact. Discovered, hidden inside of the trailer’s refrigerator unit, were portable GPS jamming devices hooked unobtrusively to a battery located inside the unit.

　　It is reasonable to believe that the individuals who planted the jammer felt that there may have been a tracking device secreted somewhere inside the shipment and used the GPS jammer to thwart the tracking of the shipment.