I can't find it now, but I've seen a couple of annecdotal posts where people with high credit limits got there credit limit lowered right after using the same c

I can't find it now, but I've seen a couple of annecdotal posts where people with high credit limits got there credit limit lowered right after using the same card at a Walmart for the first time. Maybe those people had other changes in their spending/paying habits, but if credit card companies lower people's credits, how do they make that determination to do so?