dublet

The only person liable here is the shooter.

On the very specific point of liability, while the shooter is the specific person that pulled the trigger, is there no liability for those that radicalised the person into turning into a shooter? If I was selling foodstuffs that poisoned people I’d be held to account by various regulatory bodies, yet pushing out material to poison people’s minds goes for the most part unpunished. If a preacher at a local religious centre was advocating terrorism, they’d face charges.

The UK government has a whole ream of context about this: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/97976/prevent-strategy-review.pdf

Google’s “common carrier” type of defence takes you only so far, as it’s not a purely neutral party in terms, as it “recommends”, not merely “delivers results”, as @joe points out. That recommendation should come with some editorial responsibility.