I think we are all well aware of what motivates these killers by now. Giving them more of a platform and audience won’t reduce their murders - it will bring them more followers.
We have a good idea what motivates them. Here's some quotes from professionals:
From Katherine Newman, a sociologist at Johns Hopkins University: "In general their social experience is not one of easy incorporation, ...Rather than wanting to be alone, many mass shooters have a history of struggling to connect. They experience rejection by their peers or they draw back from potential friendships, assuming they'll be rejected if they try. They believe they're perceived as insigificant."
And from Dr James Knoll, forensic psychiatrist with expertise in mass murders:
"The mass murderer is an injustice collector who spends a great deal of time feeling resentful about real or imagined rejections and ruminating on past humiliations. He has a paranoid worldview with chronic feelings of social persecution, envy, and grudge-holding. He is tormented by beliefs that privileged others are enjoying life’s all-you-can-eat buffet, while he must peer through the window, an outside loner always looking in.
"Aggrieved and entitled, he longs for power and revenge to obliterate what he cannot have. Since satisfaction is unobtainable lawfully and realistically, the mass murderer is reduced to violent fantasy and pseudo-power. He creates and enacts an odious screenplay of grandiose and public retribution. Like the child who upends the checkerboard when he does not like the way the game is going, he seeks to destroy others for apparent failures to recognize and meet his needs. Fury, deep despair, and callous selfishness eventually crystalize into fantasies of violent revenge on a scale that will draw attention. The mass murderer typically expects to die and frequently does in what amounts to a mass homicide-personal suicide. He may kill himself or script matters so that he will be killed by the police."
Are we? Because articles such as this seem to blame 8chan and 4chan (they never mention the rest of the site which has stuff from /g which is GNU stuff and the transexual and gay communities on there). Back in the 90s they blamed Doom, Heavy metal and Rap music. In the 1950s and 60s they blamed horror / slasher comics.
As for giving them a platform and an audience bringing more followers, firstly this is terminology used for justify soft censorship. Secondly in the UK back in 2010 Nick Griffin (a notorious anti-semite/racist and leader of the BNP) was allowed to speak on Question Time (a very popular show on the BBC). Afterwards we didn't hear from the BNP again because the ideas were exposed for what they were. The BNP party is effectively dead in the UK.
Almost every-time one of these racists are actually spoken to the vast majority of the population reject their message. Every-time it is repressed these ideas resurface because these people create their own echo-chambers and makes these ideas sexy as they are considered taboo.
Nick Griffin's electoral success was not killed by his appearance on Question Time. In fact, a bunch of minority political positions have had a good deal of political oxygen from BBC appearances: I'm thinking mostly of Farage in the dog days of UKIP's popularity and also the Spiked!/Institute of Ideas collective.
Griffin lost largely because there was factional instability in the BNP and then the rise of UKIP stole the non-fascist right-wing to far-right vote.
Even so, it's very difficult to kill a political movement by logical debate (or even by making them look silly). I had the misfortune to know Mark Collett (another one of the BNPers) at Leeds University. We managed to stop him making much headway in recruitment etc., but he lived for the publicity. Even when he got thrashed at Union AGMs and the like he'd be busy pitching to his potential support in the audience. Didn't work on most (he lost his votes by a landslide) but he wasn't actually trying to win. And I suspect getting his arguments attacked by a bunch of lefties and Jews didn't harm him much in his constituency, either. After all, it's all a conspiracy to stop him talking, isn't it?
Has anyone with an audience actually performed a mass shooting? I thought all of them were basically nobodies, not even their troll forum friends seems to care about them.