In the historical environment it led to people being killed by the neighborhood mob when they decided to lynch the black man[1]
In todays environment it leads to genocide[2].
It is morally laughable to compare deplatforming to the consequences of the free spread of misinformation, propaganda and hate rhetoric.
[1] https://en.wikipedia.org/wiki/Lynching_in_the_United_States#...
[2] https://www.nytimes.com/2018/10/15/technology/myanmar-facebo...