I am fascinated by the fact that Arab/Muslim  cultures cannot tolerate parody of religious matters. I expect this among radical and conservative Christian sects, but they are a minority in Western countries. In Arab culture, however, this attitude seems to be the norm.
So what would be the source of this, outside of the strictures of the Koran? I think it has to do with secularity, humanism, and skepticism.
Backing up for a bit to pose a question: Did Arab culture go through an Enlightenment?
I've been thinking about this ever since I came across the idea in a Der Spiegel article. An Arab writer (I believe he was Muslim as well) mentioned in a dismissive manner the Western idea that Arab culture had never gone through this movement. I've never read Walter Benjamin's Orientalism, so if it's mentioned in there or other significant cultural works, then mea culpa.
If Arab culture didn't go through an Enlightenment, then how does one characterize the flowering of Arab culture during the 9th-12th centuries? Looking back over what I've read and learned of Arab culture, it seems that it experienced the same initial push toward enlightenment that Western culture did, but for some reason, it didn't continue. Arabs were well known as mathematicians, for instance, and traders, and engineers...at one point. Those skills didn't catch anything else on fire. I'm not sure that it's accurate to attribute the faltering  of this rational, scientific impulse to military conquest by Christians.
It's no secret that Western countries see Arab culture as increasingly violent, but the furor over the cartoons published in Jyllands-Posten (Denmark) caught a lot of us by surprise. What could be more harmless than parody? It seems exceedingly irrational, even for Arab culture, to be so intolerant of a joke.
And there, I think, is the key.
Parody and scientific inquiry stem from the same intellectual roots. A favorite professor of mine once said that in order to be a good skeptic, one has to concede that there might actually be Truth. If one can't consider that possibility, then one has nothing to which one can compare observations. In other words, the chance that there's an answer gives one the power to compare things. And that's what skepticism is all about--what rationality is all about. The potential truth that one uses for comparison thus comes under constant scrutiny. It's always being compared to this or that.
Parody is a similar strategy. It asks us to compare the parody to the icon and to do so with skepticism toward both. Rationality and revisionism are parodic axioms, and it holds the whole of reality as its set of potential objects of inquiry.
The fury of the conservative Arab response was breathtaking, and the capping surprise was the support that came from other Arab strata. Social mobility and Westernization apparently did not make inroads into the belief that some people have the right to not be offended.
Being offended in Western culture is a cherished thing, and I don't mean the garden-variety ire one sees when, for instance, a group of citizens protest a new strip club's opening. Witnessing the offense of others is an opportunity to reexamine one's own values and beliefs. Parody is one of the most important things we can have around us, because in sparking a response, it asks us to be philosophical.
To demand that one not be offended is to demand that the philosophical not be encountered. Now that is breathtaking, indeed.
 I use "Arab" to mean "Muslim" here for the sake of brevity. I am quite aware that the two are not necessarily the same, that one is an ethnicity and one is a religion. This first "Arab/Muslim" citation is to get you to read this footnote.
 I realize that the language I use is that of absence, lack, etc. I am writing this from a Western perspective, after all.