Every time tech is used to fight crime, the “bad” guys just get better gear. The only crime-fighter that manages to always have the better gadget is Batman. Now car thieves are using GPS jammers to confuse the cars they steal, blotting out the satellite signals that the car needs to report its position to lo-jack services.

It’s not hard to do, either. A quick Google Shopping search for GPS blockers shows models on sale for under $30. They don’t even need to be powerful. In order to swamp the incoming satellite signals, a jammer only needs to put out two Watts of power. Speaking at a symposium, Bob Cockshott of “cyber security” company Digital Systems KTN said that “the strength of a GPS signal is about as strong as viewing a 25W light bulb from a satellite 10,000 miles away.” Small wonder that satnav devices take so long to acquire a lock.

It’s not just criminals who are using this tech, either. Employees whose cars are tracked by their companies use them to go off the clock, and according to the Guardian, German truck drivers use them to “to evade GPS-based road charging.”

But knocking off gas-guzzling cars and sticking it to the man are just the annoying part of the potential for GPS jammers. A 20W unit would be enough to cover a commercial airport, with rather scary results.

There is also the possibility of feeding false signals to a GPS unit, which would be harder for an operator to spot than straight-up jamming. If you start doing that to boats driven by sailors with no sextant experience and you get havoc.

Still, something good could come of this. It’s possible that people reading the story could become less trusting of their in-car satnav units and actually look through the windshield once-in-a-while. This would avoid the estimated 300,000 crashes caused in Britain every year by GPS-following fools.

Car thieves using GPS ‘jammers’ [Guardian]

Jamming of GPS signals threatens vital services [FT]