Free will is a fascinating hypothesis that is only partially explanatory of observed human behavior. ;)
To be less glib: in the US the bar is very high, but we do, in fact, have some things that we've removed from the "free will" discussion. Child pornography is the obvious example.
Yes because the process of creating child pornography is harmfully exploitative of a child, and we as a society have decided this one of the worst things anyone could do, so we've made creating, distributing, and accessing child pornography illegal. If someone disagrees with this, they're most assuredly allowed to voice their opinion on it however they see fit, obviously as long as no child pornography is involved.
Drawing a parallel between child pornography and untoward politically incorrect discussion out in the open doesn't seem like a very useful comparison, especially when I provided another recent example of a shooting that one could argue was caused by online "radicalization."
The US bar is very high to curtailing speech as a government action, and it's worth noting that the story we're commenting on is about an Australian telco taking private action. I actually don't know the law in the US around what would happen if, for example, Verizon decided to IP-blackhole 4chan of its own initiative (in general, Americans would probably rake it over the coals for diminishing consumer choice at the very least). It'd be a hell of a show if they tried, and I don't see it coming.
The example you brought up is also from the US and, I hate to say it, was probably treated differently because the US is just desensitized to the amount of violence in its culture these days. The baseball shooting was tragic, but none of the injuries were even as permanent as the ones Gabby Giffords suffered. But the New Zealand shooting was in a country far less tolerant of such intra-civil violence, and Australia already has speech constraints relative to the US (contrast their attitude on videogames to that of the US).
(... but to turn the conversation around: do you think there should have been a conversation about online radicalization after the 2017 shooting? Maybe there should have been. What do you think should have been done differently?)
Yes, Australia and New Zealand are not the US and as such do not share its free speech laws and "free speech culture(/history)." This current situation is interesting though because from what I can tell, there hasn't been any government action yet, just private ISPs taking action with their own infrastructure. This is all sort of uncharted territory and it seems like nobody's sure how to go about solving these complex issues, yet ISPs are taking preemptive action of their own accord. (I agree that if an ISP in the US were to do something like this, it would be one hell of a shitshow, again due to legal and cultural differences.)
With regards to the 2017 Republican baseball practice shooting, I do think there should have been more of a conversation about online radicalization after the fact. I'm not saying legal action should have taken place or ISPs should have started DNS-blocking websites, because a.) again, cultural and legal differences compared to NZ/Australia and b.) because there was no convenient scapegoat to point fingers at. When "right-wing" violence happens, it's very easy to say, "ah see! 4chan and 8ch at it again," because everyone basically agrees that those websites contain "right-wing" hatred. Yet, "left-wing" hatred is and has been, for some reason, allowed to take place on most major social media websites and discussion platforms, largely uncriticized. Plus, it's undeniable that this has dramatically increased in recent years, since about 2015 especially, for obvious reasons.
So you have blatant, largely unimpeded "left-wing" hatred allowed to happen out in the open on most of the Internet, while "right-wing" hatred is forced off mainstream platforms and onto fringe sites like Gab, 4chan, and 8ch... so when "far-right" extremists commit acts of violence, it's easy to say, "See, these fringe websites where all this hatred is being espoused? We should do something about them!," but when "far-left" extremists commit acts of violence, there's no easy targets to place the blame on, because the hatred happens just about everywhere and is for some reason considered to be more or less socially acceptable.
It's hard to argue that "radicalization" due to online information and opinion dissemination is anything but a major cause for concern and something that we should be investigating and having frank discussions about, but in order to do so, the discussions have to be actually frank and encompass the entire situation, something which few if any are willing to actually do. Our physical human forms have not evolved to intuitively grapple with the consequences of the existence of the Internet[0], yet just about everyone uses it every day. We should dig deep and really examine this at some point.
To be less glib: in the US the bar is very high, but we do, in fact, have some things that we've removed from the "free will" discussion. Child pornography is the obvious example.