Does it annoy you when people don't place a separator behind their groceries?

I didn’t do this the other day because I don’t really think it’s a huge deal and the guy behind me grabbed one and put it down (rather forcefully I thought). There was a moment of discomfort between us, but I stood my ground. I don’t believe in these things you see.

But some people seem to very adamant about placing a separator between their groceries… As if a catastrophe might ensue otherwise. How do you react when people don’t do this for you? Are you a frequent grocery separator yourself?