The Charlie Hebdo attack has put a focus on what Muslims believe concerning visual depictions of Muhammad, Islam's chief prophet and central figure.
A New York Times rundown of threats and acts of violence over blasphemy and insults to Islam notes:
People of many faiths have committed violent acts in the name of religion and issued threats over insults. In Islam, though, there are strict prohibitions on the rendering of images of the Prophet Muhammad and other religious depictions.
In a number of countries where Islam is the prevailing religion, such insults are crimes. Some are punishable by death.
Of course, these same blasphemy laws also affect other issues in the news. Just think of all of those stories about converts to other faiths, usually Christianity, facing legal threats or even death sentences. There are many ways for unbelievers (including "moderate" Muslims) to insult Islam, but the alleged ban on images of Muhammad is the key here.

