If you want to see the "law of the jungle ' -- rampaging mobs surging through our communities and killing you for your tuna fish -- disrupt electrical power for about five days.
Without electrical power, there is no way to store food other than canning (which most people aren't equipped to do). Hence, the food supply is disrupted (along with television, CATV, internet service, etc).
There's an old saying--"every society is three meals away from chaos". People will tolerate all kinds of fucked-up shit from their rulers...but they won't tolerate quite so much if they have to do so on an empty stomach.