What is the repercussion of criticizing Islam then?
If we live in Europe and you do it publicly, death threats and/or assasinations.
Actually, I am not worried about Islamic people at all; the ones I know are either kind and helpful (especially the older people) or they are a bit wary of western people due to the way to media portrays them. Of course they are a bit more agressive than us, but they are not at all different from our mentality only 150 years or so ago. Maybe Europeans like ourselves just grown to be less agressive.

Either way, I think the way we think about Islamic people is rather overboard, and coincides rather well with the wars in Iraq and Afghanistan, as well as Israel's urge to strike Iran. I may be an idealist, but I do firmly believe that with positive attention and care, respect when they are young, comes a long way into making them good citizens.
For the militant Islamics, see it this way; if your country is being attacked, wouldn't you fight back? I think I would, at least. That of course doesn't make their deeds in war, good deeds, but the whole situation is more than just one-sided, of course.
Back on the OP (Original Post), I think constructive critisism against any institution and/or religion should be acceptable. Using that as an excuse to attack religions, however, isn't acceptable. That only helps to put two cultures against eachother, instead of to work together.
- JC