You know, a customer at work actually brought that up with me a couple of days ago. They asked me if I was allowed to say "Merry Christmas", and I said we were, even though I usually say "Happy Holidays" unless the customer says "Merry Christmas" first, to which I return the phrase. The customer then started ranting about how we're celebrating Christmas and not other holidays. When the order was over, I flashed a smile to them and said "Happy Holidays!", to which they gave me a glare and walked out.

It's not exactly hard to be considerate of other religions, you know. Fucking zealous, close-minded religious people...