They're not stealing from the 'expired food' area.
Expired food in many countries ends up in food pantries as the date for canned and dried food has more to do with freshness/taste than actual health issues. So its already being socialized.
Unfortunately in the US, most grocers and corporate stores do not donate their food. They lock the dumpster they throw expired food in. I've heard of places that bleach their dumpsters so people don't break in to eat the food.
I do know of a handful of shops that donate, though. They tend to be much smaller.
