"A few of the radical Christian clerics exhort their followers to violence in defense of their Christian beliefs..."
The big difference being that this is always followed by official condemnation.
Where are the muslim moderates at times like these? The community leaders to come out and say, "calm down everybody, this is not what our religion is about". Absent as ever. As much as the moderate muslims may deny it, their silence speaks pages at times like these.
I even see it in westernized muslim friends of mine, who just sheepishly grin and say "but it's mohammed, our religion says we shouldn't disrespect him".