You are misinformed, and thus misunderstand part of what's going on here. It is in fact a tenet of Islam, set forth by Muhammed himself, that Muhammed's face is never to be depicted. He forbade this so that he would never be used in a statue, icon, illustration, etc. as an object of veneration or worship. He wanted to make sure that only Allah alone was worshipped.
If you look in any Islamic religious work, they avoid depictions of Mohammed. In those illustrations where that would be impossible, either his face is turned away from the point of view, or a ball of flame is substituted for his face.
And they complain when someone else shows his head as a bomb? Heck, they started it.
But they do depict him, even though they say he must not be depicted.
Oh, yes, one more thing, the muslims constantly depict jews and christians in cartoons far worse than any the west had drawn about muslims. They simply want the whole world to bow down to Allah. Well, no thanks, if I owned a paper I would be flooding it with cartoons about muslims right now. What murderous thugs these people are.
Nope, they sell pics of Mad Mo in the street for a nominal couple of coins. No secret, and it's been going on forever. They put them in their homes like we have pics of jesus.
It's a "tenet" of ours that innocent people are not beheaded - and it's a tenet of ours that respect is a two way street. Why some people think it's OK to burn a building but not Ok to publish a cartoon is beyond me. Here's my "tenet": don't burn down buildings. You can worship any fool thing you want to - you can say it's evil to step on an ant - but don't expect me to have to live by your silliness. And if you think that's extreme, would you like to live by
my religious rules?
In short, I don't give a flying flip about Islam's "rules" any more than they give a flying flip about Israel's rule's or Catholic "rules" etc. It's time from Muslims to grow up and get the chip off their shoulder.