This used to be true, but the DoD turned off "selective availability" (the intentional degrading of the civilian signal) back in 2000, and the current generation of satellites do not have the capability (https://www.gps.gov/selective-availability). What they do have though is a separate, encrypted, military broadcast that can be used for those purposes (I think the plan in those situations is to turn off civilian GPS entirely - but I think that there's no reason for that, now, due to the other navigation systems like GLONASS).

Even without selective availability gps is only accurate to within about 30’ in normal urban conditions which is more than enough to punt you over to a side street without heuristics on top.