Here's an interesting article on the looting of the Iraqi National Museum:

The most striking fact to emerge from discussions with those living or working around the museum is that, in the days before and during the looting, they saw the museum being turned into a major military defensive position by Iraqi forces.
In plain violation of the Hague Convention of 1954, Iraqi fighters occupied the museum complex and used it as a combat position for at least three days after museum staff had fled. Neighborhood residents corroborated the charges made by American forces that the Americans had come under attack from inside the museum grounds and that fighting in the area was heavy. Even as they criticized the Americans for not protecting their national treasures, Iraqi witnesses to the looting said that Saddam Hussein's forces had turned the museum into a small arsenal.
...U.S. forces have cited armed resistance from inside the complex as the main reason they could not seal off the museum and prevent the looting. In the end, they protected it only after they had defeated the last remnants of Saddam's forces in the area.
The looting began on Thursday, April 10, and lasted two days, as the battle between U.S. and Iraqi forces raged through the city.
..."Clearly there was a group of people who went through the museum filling in a list of things to steal," said U.S. Marine Corps Col. Matthew Bogdanos, who until late May led the 13-man U.S. team investigating the looting. "The person who looted that storage magazine knew just what he wanted. He could find it in the dark."
...The hugely exaggerated claims about the extent of the plunder diverted attention from the looting of ancient sites all over Iraq, a genuine cultural catastrophe, said archeologists. Unlike the museum objects, artifacts wrenched from the ground are impossible to identify or track and can easily be given phony provenances to disguise their origins. The market for Mesopotamian antiquities is likely to see a huge influx of supply over the next few years as fresh loot comes onto the market. "Anything that the U.S. military isn't sitting on is being destroyed," said Mr. Gibson. "The collectors who buy this stuff are going to be happy."