Social media companies have argued they are immune from liability (say for libel) as they are carriers of the speech of others, and do not have editorial control over the content on their web sites. They are like a phone company that is not liable for the speech conducted over their phone lines.
However, with an awareness now that social media, such as Twitter, throttles tweet exposure, edits trending tag lists, and shadow bans some content, that defense becomes untenable. Social media platforms increasingly apply editorial control over their content and look more like a newspaper, magazine or television/radio broadcaster that is liable for their content. European government leaders are pointing this out:

“The status quo is increasingly unsustainable as it becomes clear these platforms are no longer just passive hosts. But applying the existing standards of liability for publishers is not straightforward so we need to consider what is most appropriate for the modern economy.”

Source: Telegram and social media giants spanked in UK PM’s Davos speech | TechCrunch