Are Tech Companies Liable for Buffalo’s Racist Massacre? Families Say Yes.

How much responsibility do tech companies have for the radicalization of Payton Gendron, the gunman whose racist assault on a supermarket in Buffalo last year left 10 people dead, all of them Black?

That is the overriding question in two new lawsuits, the latest attempts to hold social media companies responsible when people steeped in violent ideologies they found online open fire. The suits were filed by lawyers for families of victims in Buffalo, who say that the companies introduced Gendron to racist ideas, and that their algorithms direct videos to...