All of them.
You've heard of good cop/bad cop? I tend to think of this as good muslim/bad muslim.
There are 57 muslim members in the OIC and every one of them has an intelligence/security service. They could hunt these bastids down in a few months if they wanted.
They simply don't want to.
These boneheads are doing what Islam requires.
The parents of these extremist should be punished big time. You have to raise one of these from the get go to affect their will to live. Even a dog wants to live; but not these idjits.