Criticism of Islam is an eternally touchy subject mainly because Muslims aren't particularly tolerant of criticism.It's not just the extremists either, sadly. They won't exactly blow themselves up at the slightest provocation, but you'll be hearing brutal insults, mass condemnations and even death threats from the so-called 'moderate' Muslims.
They also have a rather short fuse in general. Take Malaysia for example, a predominantly Islamic country that prides itself on being a beacon of racial and religious harmony... except it won't take long for you to realize that 99% of the Muslims here have an irrational hatred for the Jews, despite never having met one their whole lives, justifying their hatred by citing the 'horrible war crimes commited by Israelis against the Palestines'. Nevermind the fact that there are two sides to that story, or that not all Jews are supportive of the ongoing violence or even involved in the first place, all it takes is the knowledge that "Israelis have been killing Muslims, wah" and you'll have them frothing violently at the mouth whenever Jews are mentioned. Just recently, a young couple was recently sentenced to jail for posting a picture 'ridiculing' Islam(it was a fairly minor issue blown to huge proportions). Funnily enough, the response to that particular case was far quicker than the response given to actual crimes in the country. Another man who criticized Islam was kidnapped, stripped naked and had his body vandalized, with pictures being distributed on the net.
I criticize Islam whenever given the chance, because I genuinely believe its teachings to be wonky. Truly moderate Muslims are a minority, no matter what everyone keeps saying. They may not act out their aggressions, but they do harbor excessive hatred bordering on the irrational.
Just a couple of things I've observed living in a predominantly Islamic country. It's not as bad as I make it sound to be, and I do know quite a few Muslims who are rational and level-headed. Interestingly enough, they also tend to be not as religiously devout as their peers. There's a pretty telling correlation there somewhere, but I should probably stop before someone whips out the Islamophobia card and accuses me of bigotry.