What Would Happen If G.P.S. Failed?

In front of an audience of military and government officials, Humphreys fed faulty G.P.S. coördinates to a test drone aircraft from a third of a mile away, causing it to plummet. (He would later hear that officials were “shocked” upon reviewing video of the demonstration.)

.. The good news, he said, was that there were, at most, a hundred people in the world who could build a spoofer as mighty as his. For the moment, it was probably beyond the reach of organized crime or terrorist groups but “well within the capabilities of near-peer nation-states.” He spent the next few years documenting how his spoofer could induce the kinds of clock errors that might undermine power companies, telecoms, and financial firms. The last of these, Humphreys thinks, are particularly vulnerable to attack.

Why You Can’t Trust GPS in China

One of the most interesting, if unanticipated, side effects of modern copyright law is the practice by which cartographic companies will introduce a fake street—a road, lane, or throughway that does not, in fact, exist on the ground—into their maps. If that street later shows up on a rival company’s products, then they have all the proof they need for a case of copyright infringement. Known as trap streets, these imaginary roads exist purely as figments of an overactive legal imagination.

.. in China: there, every street, building, and freeway is just slightly off its mark, skewed for reasons of national and economic security.

.. In other words, everything there—roads, nightclubs, clothing stores—appears to be 100-600 meters away from its actual, terrestrial position. The effect of this is that, if you check the GPS coordinates of your friends, as blogger Jon Pasden writes, “you’ll likely see they’re standing in a river or some place 500 meters away even if they’re standing right next to you.”

..  If a given device—such as a smartphone or camera—detects that it is in China, then its ability to geo-tag photos is either temporarily unavailable or strangely compromised.