I do think we need to ask hard questions such as whether these children would have done this had they not had the internet access they had. We'll maybe never know but we need to ask these questions.
It's really important. At Molly Russell's inquest the coroner ruling was "“Molly Rose Russell died from an act of self-harm whilst suffering from depression and the negative effects of on-line content” i.e. a direct causal link was established in law. And still children aren't protected.
Given how many third factor authentication processes I have to go through as an adult online, it's clearly not actually impossible to stop children accessing this stuff - what is lacking is public pressure and political will and the lobbying might of those who make money out of misery wins the day.
I hope that more safeguards will be put in place to pick up and stop children accessing this sort of content and having the kinds of dehumanising conversations they were having about other children without anyone noticing.
We owe it to Brianna to ask if anything could have prevented this.