The Islamic interpretation of the sixth Commandment is ominous: "And do not kill anybody that Allah has prohibited except when you have a right to kill" (6:151), "....anyone who murders any person who had not committed murder or
horrendous crimes, it shall be as if he murdered all the people" (5:32), "You shall not take life, which God has made sacred, except by way of justice and law" (6:151-153).
In their Holy War, Islamic extremists are - in their minds - rightfully killing as they seek justice against their enemies. It's difficult to argue with - it's all right there in their sacred book of things to do. The infidels can be killed as enemies of Islam. Refer back to my lengthy post of several pages ago for further examples of encouragement of violence against those who do not support Allah.
I've already explained how a violent film (or computer game) is devised as fictional entertainment instead of a set of strict and deadly serious rules from a divine source. The bigger and more profound the declaration, the stronger its consequences. There is no comparison - you may as well cite the regular consumption of fast food as a similar reason why people have killed.
Also, refer back to my calculated proof that God does not exist in case you missed it. My proof is proven in that it demonstrates that God does not exist - it is functioning right now this moment. It has already been explained that the equation is demonstrated in its simplest form. It can of course be denied, but then with their blind faith the religious are doomed to live in constant denial anyway, so there you go.
http://www.youtube.com/watch?v=u1kqqMXWEFs