Couple this with the nasty trick of manufacturing the popularity of certain opinions [1] and I wager that it is pretty trivial to get most people to believe in anything and especially easy to make people think fringe opinions are actually widespread and commonplace. Coupled with the emotive fallacious reasoning of "If everyone believes/says it then it must be true" and you can make reality, at least how people see it, however you like.

I am 100% convinced that this has been abused to boost the bottom line of certain media companies because outrage gets clicks and figuring out how to induce outrage means you can farm clicks by outraging people who you've conditioned to become outraged. Increasingly often media-manufactured lynchmobs are formed over topics where you can tell by talking to the outraged people that most of them are misinformed about whatever it is they are all worked up over.

It's like the world's largest (and worst) game of Telephone.

[0] https://www.washingtonpost.com/graphics/business/wonkblog/ma...

[1] Relevant XKCD: https://xkcd.com/2159/