Why does seeing people buy food with EBT/Food Stamps physically upset people these days?

Recently at the store I got in line and saw the lady at the front paying with food stamps it was none of my business I don't care. However the guy behind her was visually upset, swearing, even turned around and told me "I'm paying for her food" and started slamming his hands down breathing hard he was almost turning red. I'm pretty sure lots of Americans are paying for things they don't want to, I'm probably paying for someone else food but getting angry and violent publicly isn't going to change anything at all. I've ran into situations like this up to 5 times one the guy started knocking things down and screaming. Is this common where you live and do you behave like this over government assistance?