A redated post.
This is the wikipedia entry on reaction formation.
If one really thought psychoanalyzing one's opponents had much validity, there would be a lot of ways to do it. I would like to invite crusading atheists to examine themselves, to see to what extent their strident atheism could be reaction formation.
Of course, believers can be caught up in reaction formation as well. I think it important, though, to be acting intellectually, and not just reacting.
I take it seriously when an atheist says "Examine your thinking and see if it isn't just wishful thinking," for example. If they say "You only believe because you want to,' knowing only that I am a Christian, that crosses the line. But I think I can say "examine yourself" without committing the ad hominem fallacy.