I suppose more than a few of us olds remember Serdar Argic's attempts to redefine the Armenian genocide on IRC.

https://en.wikipedia.org/wiki/Serdar_Argic

But Serdar was relatively easy to ignore, because it was just one account, and it wasn't pushed on everyone via an algorithm designed to leverage outrage to make more money for one of the world's billionaires. You're right: pervasiveness and scale make a significant difference.