Have someone on your doorstep saying they're with the census bureau and shooting GPS coordinates? Skeptical of the relevance of these coordinates to the census?
You're not alone.
Read this: http://libertarianrepublican.blogspot.com/2009/05/wnd-headlines-gps-census-bureau-story.html
Read about the variety of things that can be done with these coordinates here.
Slowly, almost imperceptibly, I feel we are heading towards the dystopic minutae of Orwell's 1984 and noone's doing anything to stop the steady, insidious slide.