Have any of you tried freeganism?

Essentially supermarket bin diving? I tried it once when I was waiting for something at work.I was sitting in the Co Op car park and they were wheeling a trolley full of food to the bin. I asked if I could have some, and got a quiche, some cocktails sausages, dog food, dog biscuits, a sandwich, a dented tin of red wine sauce, yogurt drinks, and some ready meals. The sell by date was that day, and the drinks had one missing thats all. I gave the dog food, biscuits and sarnie to a homeless man, and the rest to my mum. Do you see anything wrong or right with bin diving?