The internet's full of liars. Take fake news stories that spread like viruses. There's a reason why the word "viral" is used: it's because it operates exactly like a disease would.
Think about it. There's a receptive host, in the case of viral stories, a person who wants to believe BS to reinforce whatever preconceived notions or ideals that they have, and they scour for credible-looking sources to add credence to their moronic, defeatist outlook on life.
All it takes is for someone to create the story and spread it on social media and enough people will disseminate it - it's only a matter of time. It's basically how Russia was able to heavily influence our democratic process and make us look like a bunch of dweebs.
But not all fake stories are spread for the upheaval of nations of cyber espionage, sometimes people just lie on the internet for the sake of lying. But here's the thing about lying, if you're going to do it, be really good at it. Or else you should get very comfortable with being mercilessly ridiculed online.