The Supreme Court heard oral arguments last month in the momentous case of Murthy v. Missouri. At issue is the constitutionality of what government authorities did to censor speech that departed from preferred narratives.

Justice Ketanji Brown Jackson posed a hypothetical to Louisiana Solicitor General J. Benjamin Aguiñaga: “Suppose someone started posting about a new teen challenge that involved teens jumping out of windows at increasing elevations. . . . Kids all over the country start doing this. There is an epidemic. Children are seriously injuring or even killing themselves in situations. Is it your view that government authorities could not declare those circumstances a public emergency and encourage social media platforms to take down the information that is instigating this problem?”

Mr. Aguiñaga might have countered with a question of his own: What “information”? Whether government authorities would be justified in seeking to suppress such videos is an important question. But it isn’t a question about information, misinformation or disinformation.