The size of the flying saucer
When it lands it's shown to be huge, but when it's on the ground and actors are near it, it's several times smaller. Why couldn't they have built a set that represented a much larger ship, and we're just seeing less of it in the shot?
Scroll down about halfway to see the large version:
http://io9.com/5980921/the-best-aliens-land-on-earth-scenes-ever-filme d
Click on the image under "Watch Trailer" for the small version:
http://www.moviemail.com/film/56610/The-Day-The-Earth-Stood-Still-(Wis e,-1951)/
They aren't even close, and that suggested that they didn't even try to reconcile the two.
BIG GOVERNMENT = small citizen
Power is a zero sum game