I would wager they are just criminals. One of the striking aspects of totalitarian regimes is the amount of crime present in them. Criminals actually flourish in such regimes. We, in the west, have been lead to believe that at least totalitarian regimes prevent crime. Actually they don't. Evidence from Communist regimes of Europe suggests that the authorities had active ties with the criminal underworld and allowed it to thrive. In the former Soviet Union which officially didn't allow private gun ownership - had a higher murder rate due to guns than that of the United States in the 70's and 80's before the collapse of the Soviet Union- due to criminal gang wars.
I would wager, some of both. And also perhaps some truly desparate people who have starving family at home, and no other way to take care of them. Stealing from Saddam in a desparate attempt to save your family would not be a crime in my opinion. Just human nature.
Saddam's regime over the years has destroyed Iraqs people. Anyone of moral stature, of intellect, of strong will, have been murdered or exiled. There is no one left in Iraq but the poor downtrodden slaves who are too fearful to do anything controversial, and the criminals who are the Baath party. Nothing in between.