Sometimes, in order to understand advocates of pseudoscience, such as antivaccinationists, it's a useful exercise to look at their most extreme elements. Admittedly, in focusing on such loons, one does take the risk of generalizing the nuts to everyone a bit much, but on the other hand I've often found that the extremists are basically like the less loony versions on steroids. The advantage, to me, is that they are unconcerned (for the most part) with hiding the craziness at the root of their beliefs.