I was thinking more of Google, not Facebook.
Holding Facebook accountable for the actions of it’s users doesn’t solve the problem of the fake news. People want to believe the fake news and are willing to propagate stories they fear are true or want to be true. Facebook is a sharing platform, and fake news, like gossip, spreads like wildfire wherever social interactions become normal. Unless Facebook identifies and removes those individuals who actively create fake news by outright ban from ever accessing Facebook again, they will never get rid of fake news. And even if they did, they might as well squelch gossips as well.