This mechanism actually sounds like it could solve this problem. By making it policy that citations used in periodicals must link to these versioned pages, ther

This mechanism actually sounds like it could solve this problem. By making it policy that citations used in periodicals must link to these versioned pages, there is at least a traceable record about when something cited incorrect information. I could also see this being a service to inform authors when their citations have been invalidated. A truthiness score of an article or blog post could be based on citation accuracy and could be assessed by a third party that specializes in fact checking, but initially it could be done by measuring when a particular like in a Wikipedia article has changed and whether or not that change affects the meaning.