I disagree with your insistence. I find your premise silly.
And yet you present nothing to show it unsound.
Why don't we pass a law that will prevent murder? Because a law cannot prevent murder.
Why don't we pass a law that will prevent assault? Because a law cannot prevent assault.
Why don't we pass a law that will prevent rape? Because a law cannot prevent rape.
Why don't we pass a law that will prevent robbery? Because a law cannot prevent robbery.
Why donl't we pass a law that will prevent criminal posession of guns? Because a law cannot prevent criminal posession of guns.
What you want is no different that requiring CNN to present a story to the FCC so the FCC can determine if the story slanders someone or is an act of libel, and then allow/disallow the broadcast of the story on that basis.
Yanno................maybe if CNN and FOX were required to submit their stories to be fact checked, then they may not have done the full hour of bullshit reporting stating that the FBI had taken custody of a "brown man". Maybe they would have realized that the FBI had just released the photos to the public for identification.
And none of the two people were "brown men".
Additionally...................maybe if those Harvard professors who have been proven to be so horribly wrong about austerity had allowed their work to be checked before it got published, then the GOP who have cited that report wouldn't be shown to be bloviating gas bags.
And.....................fwiw....................I think that the 2 people shown on the cover of the NYT under the "bagmen" headline (who weren't even close to being the real bombers) should sue them for libel and defamation of character.
Like I said..................having someone check your facts isn't a bad thing. Matter of fact, it can keep you out of hot water like the examples mentioned above.