In the early days of GPS, around 1991 or so, I got a notice from Magellan that, oh, by the way, the GPS system was going to be out of commission for about three days just before Christmas (probably so that Santa could navigate traditionally). I am not sure just why this occurred, but there it was.

I think of that whenever I search out my trusty topo map, a piece of equipment I was familiar with long before GPS showed on the scene. GPS is very, very nice and it has simplified my life remarkably, especially in regard to locating archaeological sites, but i won't trust everything to a system that can be disabled or degraded (remember Selective Availability?) by The Powers That Be. You are absolutely right.