In all seriousness having some kind of law in place to make the spreading of false information illegal, punishable by a fine perhaps, might be a good idea. It would make people think before they speak.
Of course people would balk at such an idea. Yet we already have such legal limits on free speach in the form of libel laws. As a consequence people have to be careful what they say about others in public. If such libel laws are necessary to a degree to protect people's reputations against false claims then why not a law against false claims in general?
It could just involve small fines like speeding, not a major crime, but it would factor in some element of justice against misinformation. Of course who determines what's true and what's misleading? Well that must already be being determined in libel cases. If it's good enough there...
Perhaps the law could be aimed at public pronouncements that are aimed at an audience over a certain limit, eg 10,000+. Would it therefore really affect anyone other than journalists and politicians and force them to be more careful about their facts and not to lie?