Are hate symbol bumper stickers legal?

I genuinely don't know. I was driving behind a work van that had a "pure blood" bumper sticker alongside a Nazi SS symbol. It's upsetting to see, but I'm not sure if it's a reportable offense, or just something to sadly shake my head over? Advice?

Edit: thanks friends! I'll try calling it in to non-emerge. Unfortunately I only saw the rear of the vehicle which didn't have a company name, otherwise I'd gladly name and shame!