This was bound to happen, given the way soldiers in the US army seem to be taught to treat people in countries they occupy. They dehumanise them by giving them names like 'gook'. This makes them easier to kill and mistreat (the Nazis did the same thing with the Jews and Russians).

The fact that the US military doesn't care about Iraqi civilians and is happy to fire into residential areas and shoot people dead who look like they're up to no good (regardless of evidence one way or another) means when their soldiers are put in charge of prisons, they don't see the people inside as human.

This is the real irony of the Iraq debacle - the most powerful nation becoming more like the enemy they profess to despise.