On 14 February 1989, the day of the funeral of his close friend Bruce Chatwin, a fatwà requiring Rushdie's execution was proclaimed on Radio Tehran by Ayatollah Khomeini, the spiritual leader of Iran at the time, calling the book "blasphemous against Islam" (chapter IV of the book depicts the character of an Imam in exile who returns to incite revolt from the people of his country with no regard for their safety).
So Ayatollah Khomeini was butthurt over his portrayal by proxy, and decided to abuse his power to murder his critic. What does that have to do with Islam, or any religion whatsoever?
This has nothing at all to do with a 'normal distribution', and everything to do with officially sanctioned violence.
Which, in turn, has nothing at all to do with religion. It's state officials - or someone who wishes to replace them - organizing violence using religion as a smokescreen, since it happened to be handy. But any excuse would have served a tyrant, or those wanting to be them.
The real enemy is the memetic complex that combines a hierarchy of power with the idea that violence and violations of everyday morality are okay when done in service to a cause. Whether this blood-soaked pyramid is dressed up as Islamic, Christian, nationalistic or ideological decorations is irrelevant. Not perceiving this underlaying structure is what leads people to give up their freedom and their very selves to act it out in a largely meaningless conflict. Thus 9/11 led to Patriot Act and Iraq War, which then led to ISIS. The real enemy is still there, and will remain until someone figures out how to bomb the noosphere. Until then, it would be wise to avoid feeding it by buying in to the lie and newest $ENEMY.
Violent lunatics - and even or perhaps especially suicide bombers - are not the real enemy. Neither is their nominal cause. What's actually going on is that the idea that this kind of behavior is okay in the service of a cause somehow came to exist and, by an unfortunate accident of cultural evolution, happens to cause behavior that helps perpetuate and escalate conflict, which in turn perpetuates it. Thus we have a cultural virus that basically uses your own power and instincts for self-defence to enslave you. Nasty stuff.