You're not one of them... they know who they are!
I agree
I agree, but only to a point
While I agree that anyone who really wants it will find a way to get it, IMO, making it much harder to find necessarily means the number of people who see it and would be affected by it are reduced - if only 100 people are able to view it, there is much less chance of a potential copycat using it as inspiration than if 100,000 or a million view it - its simple arithmetic, a numbers game.
IMO, the argument to not ban this material is a similar argument to the flawed one that gun rights advocates make, that if a step is not a 100% solution to all the problems then do nothing. I vehemently disagree with that view. IMO, if a proposed step fixes 5% of the problems, then its a movement towards a full solution. Another step fixes 4%, and another 6%, and another 3%, and another 5%, and before you know it you're almost 1/4 of the way to a complete solution.
Quite aside from it being very unfair to the victims' families to have a video of their loved ones being brutally and systematically slain, legally allowed for anyone to view, there is also the issue people who are like minded with the shooter, using it to gee up their fellow scumbags, and encouraging them to do the same. Sure, people who are determined to get a copy will do so, you'll never stop those, but that does not mean it should be made easy to do. Making it easy to obtain means it can easily be seen by really young, or unintelligent, easily influenced people; the kind of people who would not necessarily have the skills to find a copy if it was banned.
Making this information harder to get will decrease the chances of someone becoming radicalised - the easier it is to obtain, the more people who get to see it, the more chance there is of the wrong person seeing it and that will lead directly to another similar incident.
Not "preaching to the converted" (as you put it) is all well and good, but there isn't any need for us to aid the converted in their recruitment efforts.