You would be amazed how many people wouldn't feel a bit embarrassed taking food from a food bank even though they're not poor. I assume that some would even do

You would be amazed how many people wouldn't feel a bit embarrassed taking food from a food bank even though they're not poor. I assume that some would even do it just to save some money. Then when you take into consideration that there are organized beggars and such, I believe they would also take food and try to resell it, etc. As you say, it doesn't seem very German, so I would bet that there probably was a reason to include the checks.