The key precedent is from a different era. In 1969, in Tinker v. Des Moines Independent Community School District, the Supreme Court allowed students to wear black armbands to protest the Vietnam War but said disruptive speech, at least on school grounds, could be punished.
Making distinctions between what students say on campus and off was easier in 1969, before the rise of social media. These days, most courts have allowed public schools to discipline students for social media posts so long as they are linked to school activities and threaten to disrupt them.
A divided three-judge panel of the Third Circuit took a different approach, announcing that a categorical rule would seem to limit the ability of public schools to address many kinds of disturbing speech by students on social media, including racist threats and cyberbullying.
In a concurring opinion, Judge Thomas L. Ambro wrote that he would have ruled for the student on narrower grounds. It would have been enough, he said, to say that her speech was protected by the First Amendment because it did not disrupt school activities. The majority was wrong, he said, to protect all off-campus speech.
In a brief urging the Supreme Court to hear the school district’s appeal, the Pennsylvania School Boards Association said the line the Third Circuit had drawn was too crude.
“Whether a disruptive or harmful tweet is sent from the school cafeteria or after the student has crossed the street on her walk home, it has the same impact,” the brief said. “The Third Circuit’s formalistic rule renders schools powerless whenever a hateful message is launched from off campus.”
The student, represented by lawyers for the American Civil Liberties Union, told the Supreme Court that the First Amendment protected her “colorful expression of frustration, made in an ephemeral Snapchat on her personal social media, on a weekend, off campus, containing no threat or harassment or mention of her school, and that did not cause or threaten any disruption of her school.”