This same kind of problem presents itself in the bar world where a few people object to having smoking allowed, yet choose to go into those establishments and force others, including the business owner to conform to their views. Its not as though people don't have the option of going some place else. And yet, in the United States a few ruin it for the many... why is that? Its a symptom of a much larger issue.
More to the point, all of us (including myself) have been talking about the ethics, and have indeed ignored the issue of how it could be accomplished. This thread wasn't asking if it was right, it was asking how to accomplish it because that's the business choice he was making. So to tell someone you wouldn't help them even if you knew how is a waste of space and I argue every bit as rude and irrelevant to the initial question (which he has already solved).