Anti-religious speech is often criticized in a way that goes beyond refutation to a suggestion that it is somehow socially unacceptable. Consider Tom Frame's recent attack on what he calls "contemporary anti-theism," in which he includes such books as The God Delusion, by Richard Dawkins:
When it becomes acceptable, and even admirable, to mock and ridicule a person's religious convictions and customs — and especially when the intention is to provoke an indignant reaction — the next step is to prohibit the expression of religious sentiment in all public places and forums.
But this claim verges on paranoia. Frame is Australian, and should be well aware that there is no prospect in his (and my) home country of any prohibition on public expressions of religious sentiment - though he claims, vaguely, that there are "signs" to the contrary. If he were writing in the American context, where the presidency is intimately linked with religious ritual and involved in interaction with religious leaders, the claim would appear even more bizarre. The freedom of speech enjoyed by "contemporary anti-theists" is more than matched by that of their religious opponents.
Accordingly, Frame is legally free to liken these examples of "contemporary anti-theism" to religious fundamentalism.
But although this slur is perfectly legal, it is unfair: Frame suggests that "contemporary anti-theism" has "some of the characteristics of fundamentalism and, like all fundamentalisms, needs to be opposed." But which characteristics of fundamentalism is this anti-theism supposed to show? Frame does not say, and it is not at all clear.
For example, the anti-theists he refers to have no holy text that they treat as inerrant: they may give respect to each other's writings or to classics of science such as Charles Darwin's On the Origin of Species (1859), but that is a very different thing. They do not show extreme resistance to modernity through acts of violence, resistance to science and scholarship, and subordination of women. Dawkins and others may be confident of their positions, but not with the extreme dogmatism that clings to a position even when it is plainly contrary to robust scientific findings (liberal or moderate religious leaders may be equally confident of their positions, but that doesn't turn them into fundamentalists).
Frame appears to use the word "fundamentalism" for its hurtfulness rather than its accuracy. That is, of course, his legal right in a liberal democracy. However, his analysis exemplifies the illiberal view that satire and robust criticism are illegitimate forms of speech when directed at religion.