I have a very good friend who has taught collegiate level debate for forty years. Just before he retired, he did an experiment where he and his students would actually do what you are proposing here and point out, list, highlight and rebut the various forms of argumentative cheating on Facebook and Twitter and see what happened. The result? Of the thirty students in one class, seventeen were banned from groups and had their friends list drop to below 50 people. The remaining students found that there followers dropped, that they received less over all views, and that they became targets of more and more abusive comments with threads that would begin as discussions and quickly de-escalate to that all time internet favorite the argumentum ad hominum. That pattern held good across eight classes and 240 students (give or take). I grant that one professors off the cuff experiment does not equal solid research but it is perhaps a bit disheartening.
And that leaves out both cognitive dissonance and the backfire effect. No one wants to be proven wrong, and many will fight for their worldviews and the facts that fit them, even facts that are not facts.
And given that people also frequently admit to not using the (biased but) existent research tools that are already out there why would they bother to search for and use a research tool designed for something like this? I can see such a site rapidly being used as a weapon by one side of an argument and being shouted down as "fake news" by the other.
Also, just as an aside, I am a student at Duke University- School of Medicine and we are absolutely FORBIDDEN to use Wikipedia or any other crowd-sourced knowledge base as a source in our own researches. As one of the administrators pointed out, at least eleven of the professorial staff and hundreds of the students contributed to Wiki at any given time and it was a common hobby to go rewrite a rival's work.