Regarding the ISIS fighters in particular, I think of it like gut bacteria. We have lots of bacteria in our stomachs. Some of it is good, some of it not so good. If the bad gut bacteria overpopulate, it threatens not only the entire digestive system but also the host too. Therefore, we avoid canned goods with bulges in them as it’s a sure sign of botulism. Avoiding the canned good is a subconscious or automatic process whereby you vet your food. It’s not that your racist against that can of grapefruit, it’s just that you know if you buy it and put it in your house, then whoever eats of it will either die, or they’ll end up getting sick.