Starving people are desperate, violent people. From Jeff Thomas at internationalman.com:

Recently, I was in a pharmacy and overheard the pharmacist say to someone, “There’s so much unpleasantness on the news these days, I’ve stopped watching.” The pharmacist has my sympathy. I’d love to be able to ignore the deterioration of the First World. It is, at turns, tedious, depressing, disturbing, and infuriating.
Unfortunately, we’re now passing through what, before it’s over, will be the most life-altering period in our lifetimes. As much as we’d like to behave like ostriches right now, we’d better keep our heads out of the sand and be as honest with ourselves as we can if we’re going to lessen the impact that these events will have on us.
I cannot emphasize too strongly the importance of a possible shortage of food. History is filled with examples of cultures that would endure most anything and still behave responsibly… but nothing causes greater, more unpredictable, or more violent behaviour in a people than a lack of food.