Hate speech, bullying, none of that shit needs to be protected speech. It's not as delicate or complicated as people who generally aren't on the receiving end of it try to make it out to be.
One sort of obvious case where important speech was classified as harmful is facebook's recent spat with the prime minister of Norwary over them censoring the famous photo of "Napalm girl," a young, naked Vietnamese girl running naked in the streets from a Napalm attack.
(Hell, the ex-Reddit CEO's since confirmed they had a history of IRL harassment campaigns against the families of Reddit admins who didn't go along with them.)