For example, T-Mobile is a platform. They aren't responsible for anything you say when on the phone, using their network.
CNN is a publisher. They are responsible for anything that gets posted on their website, and can get sued accordingly.
Social media companies want to choose what is posted on their website, but also not be held responsible for anything that is posted on their website. They want the perks of being a publisher, and the perks of being a platform.
Obviously there are arguments made on both sides. But that is the general disagreement, if I understand correctly.
CNN is a publisher.. they pay people to be on TV, they pay people to write articles. Of course CNN (the company) is liable for what it puts out, because they are literally creating 100% of the content and paying people to do it. So if they are slandering someone with no basis, it's logical to say "Uh CNN is literally paying people to write lies to mislead people".
Now let's take a site like HN. People post articles here, people comment on articles. HN isn't "creating" any of the content like CNN. So obviously some random person posting a story or commenting complete bullshit is not HN's goal.
Now what's the argument... that as soon as HN starts to flag something as misleading, remove "spam" (who determines what is a spam article?), then suddenly they are put into a publisher realm and can get sued for what is or is not on there?
I mean.. to me that is LAUGHABLE that someone wants to argue as soon as a site like reddit/twitter/hn starts to do anything to the content they treated like a publisher and are liable for the content. This already happens a billion times a day across all those platforms anyway.