North Korea is working on a GPS jamming device that would work with an effective range of over 100 kilometres. Yes, this would be very frustrating for any foreigners who are trying to make their way around Pyongyang, but it’s not like North Korea is terribly open to random tourists either. This clearly has more of a military application, disrupting GPS signals to the point of making them utterly unusable.
From what I remember, US President Barack Obama uses a MacBook Pro. Canadian Prime Minister Stephen Harper uses a ThinkPad or some other sort of regular Windows-based PC for his computing needs. What about Russia? It seems that Russian President Dmitry Medvedev takes his security a lot more seriously, he’s hauling around one behemoth of a laptop.