Everyone is entitled to their opinion but the effect of violent images on peoples behavior is undeniable.
This is what I have a problem with. Where is your proof that it's "undeniable?" That is an extraordinary claim that requires extraordinary evidence. Yet all you can provide is your opinion on it. That is not evidence, let alone proof.
This is the EXACT same argument Al Gore made about the human influence of Global Warming. Although I'm not arguing for or against this particular issue, he said that Human Caused Global Warming is undeniable, without showing much proof, and while hundreds of scientists were questioning this claim, with evidence of their own. And of course, he would refuse to debate any of these scientists because he believed his opinion was undeniable.
The problem is, it is YOUR opinion that violent images affect people's behavior. The actual science of it is inconclusive. If you are going to make the claim that your side of a controversial argument is "undeniable" you must be willing to provide PROOF (not just some evidence, not just a single study that seems to indicate, etc) of it. If you cannot do it, then it is simply your belief.