I don´t know how the Undertale fandom got its infamy but we pretty much know how the SU events happened and we (the bridgefag and me) have discussed it before.
It makes look any other fanbase like angels in comparison because while, there can always be drama in between, here and there, /mlp/ and bronies in general never got close to leading someone to die and much less after its hype period. Sure, there were menaces for the writers in 2011 and 2014 for Amy Keating Rogers I think, but the fanbase never took it that far as Tumblr did.
Cringe is one thing, encouraging the death of a fan for her art style about the Steven Universe show (and FiM as well) is too insane to dig.
I guess you may have heard the case at some point. I can go further with details with the help of the bridgefag but I am linking the KYM post about it for now.
