It's already a common troll[1] to just post "FAKE" in anything where the evidence is difficult/impossible to verify. There's a whole subreddit, /r/NothingEverHappens, devoted to making fun of this troll, and adding politics/culture war to the mix will just make the backlash to people who call "FAKE" that much worse.
[1] "Troll" as in "derailing tactic used by people who don't know or care if it's really fake or not" simply to be extra-clear. In politics, throwing out chaff and using derailing tactics to make it effectively impossible to have certain discussions in open fora can be a good way to prevent inconvenient ideas from being spread, in addition to the usual tactics around sowing uncertainty and confusion among the enemy.