Reuters: U.S. troops build wall of sand around Iraqi town
SINIYA, Iraq, Jan 10 (Reuters) - U.S. soldiers fed up with almost daily bomb attacks on their patrols near Iraq’s main oil refinery are taking drastic measures to fight their shadowy enemy — they’re walling in an entire town.
Posted on January 10th, 2006 at 3:17 pm

Now where did they get that idea, do you think?
This is all Macro stuff and the great game etc.
But it is worth reading in full.
http://www.atimes.com/atimes/Central_Asia/HA10Ag01.html