On the regular occasions that the shit hits the fan, the social media companies try to pretend they're invisible, and to keep the focus solely on the human who wielded the real-world weapon.
But the companies' profits depend upon engagement. So they farm our attention with whatever grabs it most. Emotions of anger, hatred or outrage are strong, reliable drivers of engagement, so that's what they farm. Whether it's a story about a cheeky fucker next door neighbour, or death threats against this week's Hate Target, it's all creating profit for the companies.
So no, they're not invisible. They're curating what we read in order to manage us, to manage our emotions, to keep us right where they want us: glued to their sites.
I'm saying all this on Mumsnet, so clearly I'm not against the existence of social media. But there are some behaviours by social media companies which are a massive, massive problem for those of us who have to live in the world they now dominate.