ok, so now the obvious question becomes, who fact checks the fact checkers? i don't blame facebook, but the people that have been asking for this i guess are about to get what they deserve: more consolidation of the power of persuasion of the masses into the hands of facebook. want to instantly discredit a story? just UPDATE stories SET disputed = t WHERE ID = ?
I think you misunderstand the format of a fact check. It's a distinct piece of content that has its own schema.org markup. It should include only editorial analysis and not opinion. It features reference sources and encourages readers to visit them. It is in its ideal form pure objective journalism. Sites adorn themselves with cute logos about the veracity of the claim but really they should be serving a compilation of facts. If they fail to do so regularly Facebook's credibility is on the line so they will be ensuring they only link to quality sources.
They couldn't just batch discredit a topic because they need something to link to.