Geoff Manaugh of Travel and Leisure magazine (yeah, seriously):
Lines of traffic snake through the centers of buildings; monuments migrate into the midst of rivers; one’s own position standing in a park or shopping mall appears to be nearly half a kilometer away, as if there is more than one version of you on the loose. Stranger yet, your morning running route didn’t quite go where you thought it did.
It is, in fact, illegal for foreign individuals or organizations to make maps in China without official permission. As stated in the “Surveying and Mapping Law of the People’s Republic of China,” for example, mapping—even casually documenting “the shapes, sizes, space positions, attributes, etc. of man-made surface installations”—is considered a protected activity for reasons of national defense and “progress of the society.” Those who do receive permission must introduce a geographic offset into their products, a kind of preordained cartographic drift. An entire world of spatial glitches is thus deliberately introduced into the resulting map.