> Why does saying that Hillary Clinton is guilty of something need to stop?
That's a too-literal reading of the comment. The implication was clearly that what needs to stop is lies that claim Hillary Clinton is guilty of something she's not.
Maybe the solution to the problem is pressuring Facebook and Google. Maybe the solution is changing tech culture. Maybe the solution is more aggressively demoting fake news and promoting debunking of fake news. Even if you want a governmental component, maybe we should only go so far as a law requiring advertising networks to make it easier/possible for an advertiser to blacklist who gets their money (I know people who have tried, failed, and ultimately gave up on trying to prevent their ads from showing up on Breitbart).
The only sane solution to this is to educate the masses, give them the tools to may be verify facts ...etc.
(I'm in favor of banning organized news manufacturing. But I fully acknowledge that it's not practical and leaves a lot of room for bias. If President Trump gets that power, there's nothing stopping him from banning CNN entirely and I'm pretty convinced that he would.)