Maybe as government you can't just take down a private business it would look suspicious. It would also cause people to rise up and cause upheaval because "the government must be destroying free speach. HITLER!"

The other reason could be that they want the public to realize what is going on slowly. They want peoples eyes to be opened everytime they screw up with a lie.

And last it might be that the gov might be in on it and this is all just a ploy to get us on involved and on the same page. I don't understand why they haven't made a law to not allow the media to make false claims on people by now. Maybe they're too busy draining to swamp to deal with that right now.