In our article in Comment is Free, Udo and I say this:
In many situations, it is better to be civil, as Paul Kurtz has pointed out, but satire and mockery have traditionally had a legitimate place whenever absurd ideas are joined to power and privilege. Enlightenment thinkers such as Voltaire often used mockery to show the absurdity of ideological stances — including religious ones — that were considered sacrosanct. Mockery is one way of saying that a view does not deserve to be taken seriously. Religious views are fair game if one can also show, on a more serious level, why the view in question does indeed not deserve serious respect.
Perhaps some rationalist or humanist organisations, such as Kurtz's venerable Center for Inquiry, do have good reason to maintain a scholarly and dignified brand image. But there is also room for the younger, brasher atheists whom Kurtz inaccurately brands as "fundamentalists", and, in any event, there is a world of difference between appropriate civility and keeping quiet.
I would have thought that this was fairly clear.
* We are not denying that civility is often "better" or "appropriate". We say that it is.
* We are denying that we should have to shut up or engage in self-censorship, as opposed to engaging in appropriate civility.
* We think that there's a place for mocking absurd ideological stances, and we define what that place is: where it could be shown, on another level, why the stance is absurd. I'll add that comedy, parody, ridicule, etc., are often useful to get people to look at something from another angle, when they are used to seeing it in a way that makes them blind to the absurdity.
Nowhere in the article do we defend merely insulting people with whom we are engaged in debate, or mocking ideas merely for the sake of hurting feelings. (To be fair, though, I'm not above making fun of powerful opponents such as the pope. This is less defensible, but it's mostly harmless when fun is being made of powerful authority figures, rather than of the powerless.)
Good Christian apologists don't refrain from mocking ideas that they disagree with and consider (rightly or wrongly) to be absurd. Anyone who is at all familiar with C.S. Lewis knows that he did this all the time. Some of his mockery of what he considered absurd naive views of progress, in Out of the Silent Planet for example, is very funny even if not entirely fair. Lewis also had no qualms about making fun of powerful opponents such as Wells and Haldane. In short, we don't suggest that atheists do more than is already done by people who defend religious positions. So why is what we are suggesting not almost uncontroversial?
What I would never defend (and I'm sure Udo would agree here) is referring to opponents by dehumanising epithets such as "rats", "vermin", etc. There is a huge difference between parodying or mocking an idea, or even the eccentricities of a powerful individual, and referring to opponents as if they are sub-human. I thought that the thread a couple back might have led to some thoughtful discussions of these kinds of important distinctions.