To go online these days is to be drowned by the hate burbling around openly, shamelessly and dangerously. Anti-Black, antisemitic, misogynistic, homophobic, transphobic — you name it. Freedom of speech, they cry. Or is it bigotry? Free speech and the competition of ideas it allows are important to democracy. But speech without limits only leads to a cesspool of toxicity. The hate visible online spills over into real life — in brutality, in ominous business acquisitions and in policy. And it’s all being done in the name of “freedom.” Twitter’s Elon Musk era, for example, although only days old, has...