My grandmother and I would go dumpster diving behind a Target many years ago to get the flowers and plants they'd throw out thinking they were beyond saving. Got hundreds of dollars worth of plants and a great looking yard.
When I worked at McD's I'd sometimes surprise a bum in the dumpster. When the food in the bin got 10 min. old we were supposed to put it in a trash can and count it for inventory. I'd bring that bag of untouched, unopened food out for the bum. Couldn't let the manager see you doing that; they didn't want a crowd of bums hanging out in the dumpster corral.