The use of a GPS jammer is banned both in the UK and in the USA and in other European countries. The sale of such devices in the UK seems to be unlawful, with a likely fine of and a stock box.

A legal loophole does not mean that purchasing and possessing is ethical, because even though Ofcom has closed UK websites with GPS jammers the UK public is continuing to purchase gadgets from foreign sellers that offer gadgets in their auction pages. Their availability means that they are more frequent on British highways, but used illegally, with potentially destructive consequences.

In August 2012, a GPS device was checked at Newark Airport, USA. The unit crashes on a weekly basis and the trigger has been blamed on a GPS jammer trucker. He used the jammer to conceal his movements from the GPS trackers of his colleagues. The lorry driver was arrested and fined. The US authorities however announced they would be taking more punitive measures.

More clearly, the GPS jammers screw up the GPS signal in their immediate area. Based on environmental conditions and power production, an intrusion bubble with a radius of up to 300m will be created.

Professor David Last finished a lighthouse trial at THV Galatea in 2010. He wanted to research the effect of a GPS jammer on the ship's new navigation systems. His findings were amazing.

Any machines shut down when the jammer was triggered. Alarms sound like a failed gyrocompass and a radar system upgrade. The positioning system of the satellite failed. Even the satellite communication system stops to change the directional antenna. The team was well trained and conscious, as they knew what was going on, but they were still shocked like us.

Globally over a billion GPS recipients are available-but only about 10 per cent use GPS for positioning and the remaining machines sync their own devices concurrently over the GPS network. Accordingly, GPS recipients would be relevant for cell towers, power grids and even cash-points.

In addition to being dangerous for air and sea networks, GPS jammers hamper the routing and preparation of ambulances, rescue systems and other vital facilities. Safety experts described the situations and the deadly effects of GPS jammers and blockers for freight hijacking agents on a busy shipping path like the English Channel.

In fact, online GPS jammers with comparatively low energy can disrupt GPS in a far wider radius than a car – and can disrupt their signal much more than a satellite system. To know more about this system, you can visit http://www.gpsjammers.org/.