They feel like "society" has oppressed them all their lives. Probably people that have been on welfare for generations and now they see a chance to steal from people who worked their whole lives.
It is important to understand how people view you. You think you are a hard working taxpayer, they think you are their oppressor because you have more than they do.
"... people who are oppressed all their lives, man, it's an opportunity to get back at society," he said.
Call Jesse Jackson & Al Sharpton...
People loot after every disaster. This shouldn't be a surprise.