Is Islam More Violent Than Other Major Religions?

This was the topic being debated in the wake of the Boston Bombings on Real Time with Bill Maher. On its face, this proposition appears patently offensive.  However, Maher debated

Brian Levy, the director of the Center for the Study of Hate & Extremism at California State University in San Bernardino, about the Boston Marathon Bombers’ Muslim faith playing a role in their terrorism

“It’s not like people who are Muslim who do wacky things have a monopoly on it,” Levy claimed. “We have hypocrites across faiths, Jewish, Christian who say they’re out for God and end up doing not so nice things.”

Maher, true to form, called his guest out and said his premise was “liberal bullshit.”

Maher concedes the obvious, that not all Muslims are terrorists.  Instead, Maher makes a slightly more subtle argument, that Islamic extremists are more violent than Christian and Jewish extremists.  

Is this empirically true? If so, does it mean anything? Does admitting this “truth” cause more harm than good? Undoubtedly, Levy’s point is also true, that such a stereotype harms the vast majority of peaceful Muslims.