As for me, I appreciate the fact that some of these 'foods' aren't available or are out-and-out banned. In my opinion, some foods are potentially too dangerous and not worth the risk. Others are created or harvested in ways that seem so unethical, that consuming them seems beneath the dignity of otherwise caring, good-hearted people. Again, that's just my opinion.
There are some behaviors many of us have seen that may immediately come to mind. Brazenly cutting in line is a HUGE no-no. That should be a given. Insulting people seems fairly obvious, but I've still seen it happen. Heaven help the person who goes after the last bag of Flamin' Hot Cheetos when THESE people are nearby.
As an essential business, the whole world was depending on grocery stores to continue to provide access to food, and they did an incredible job of serving their clients.