Excuses,excuses,justification,reasons and etc.
It comes down to morals.
They are just looting for food, water and necessities. Looting is looting.
How many NIKE shoes can a person eat?
All these goods in the badly flooded parts of the city are or will soon be ruined. It's not like anyone is ever going to go back there and claim the stuff.
This is one reason why the go/stay call is so hard for many home owners, leave and your stuff gets looted, stay and you risk your life. I think New Orleans is a special case in terms of looting, most of the city is under water and will be for months, all the stuff will ruin in that environment, normally I would be very quick to come down hard on "looters" as the real owners will be back to claim thier stuff, just not sure that is the case here.