"With all the time and energy cartographers spend preparing maps, it makes sense that they would want to protect their investment. One of the ways they do so — although they don’t always admit it — is by including “trap streets,” deliberate mistakes added to maps to catch unsuspecting copyright violators. These may include fake streets, as the name suggests, but the term is also applied to other erroneous cartographic data included to embarrass those who might steal it. Usually, these “mistakes” are minor: tiny (and entirely false) bends in rivers and roads, or slightly altered mountain elevations."