First, I feel that I need to share my feelings on prejudice. Prejudice means just what the word implies - to pre judge. This can be anything - age, race, skin color, hair color, and as we know, body modification. I'd also like to point out that I feel if you examine someone's actions or words that you're no longer prejudging them, you're judging their character that they have shown you.

Now moving on to your question about "What could I have done?":

First: "You could have been negative."

Yes, you very easily could have been negative, but I think this is the last option that anyone should resort to. If you lashed out at them and made a scene, then what everyone in the restaurant that was not privy to what the couple was saying would have seen some younger person flipping out on this old couple for no reason that has all these mods. In addition to that, the old couple would have felt justified in their assumptions of you by your actions. So for all of five minutes of vindication, you can easily help sway people's opinions of you that have not prejudged you, but judged you on your actions. It seems like a lose/lose situation to me.

The second question: "I could have seeked them out and pointed out their rudeness, presenting myself as intelligent, good mannered and no different from a non-modded person that they would not have requested to be moved away from." seems to me as futile as the first, but for different reasons.

This couple has already proven themselves to be horribly ignorant. We've seen this by the fact that A) they made rude comments about you loud enough for you to hear them and B) they even asked to move to another dining area while you weren't doing anything to them other than eating your meal. This says to me that they have already made up their minds about your character and have an extremely negative feeling towards you (for no reason at all!). Thus bringing us back to them being prejudiced. I'm prone to believe that if someone is so close-minded to believe such strong feelings about another person without any proof at all, then they're beyond being rationalized with. I know this sounds horrible and it also sounds prejudiced of me, but when you consider the fact that these people have proven to us what their character is, I don't find it accusing or prejudiced.

The last option: "I could do what I ended up doing: nothing." is what I always choose to do.

When people effectively lash out at someone simply because of differences with no other reason, I don't believe that the person even cares about the type of person they're lashing out at. In many cases, even intelligently talking to them is perceived as being snide or rude in it's own right. Sometimes not doing anything is the best solution. While I believe we'd all like an option where you could prove those people wrong by saying a few words and showing them you're a nice person, in most cases, I don't believe that's really an option. So the best thing we can do, our last option, is to slowly change popular perception by silent example. By not lashing out and not confronting people we're effectively not proving these people right. Given the mindsets of someone that's going to be so prejudice towards someone else, there's nothing we can really do to prove them wrong.

From my point of view, you did everything that you could do without giving yourself and the body modification community as a whole a bad name. Not doing anything in many ways is the most difficult thing to do, and for that, I commend you.