Replying to Fans taking it too far?

Okay so I work at a place called ShopKo, which is similar to a Target or K-mart, and if you still don't know what I am talking about, tough luck. Anyway, it was getting pretty busy and normally I don't work the register, but I hoped on one to help out and that is when it happened. There was a man purchasing some shit and he was wearing a T-Shirt since it was about 90 outside. I saw his left fore arm and guess what I saw... a tattoo. Now normally ink is ink, and it means something to the person, but I knew what this tattoo was of right away. It was the fucking Dark Mark from Harry Potter that all the death eaters have on their arms. I asked him just to be sure, I said, "Sweet tattoo, does it mean anything?" (just so i wouldn't look retarded if I was wrong) and he goes "Yeah i'm a big fan of the Harry Potter series so I decided to get the Dark Mark tattoed onto my arm." I was like "Thats cool". I mean I can understand waiting in line for the book and possibly even dressing up or whatever for it, I mean everybody gets stoked on something. But this guy took it too far. What do you think NS? Discuss.