The Supreme Court ruled 8-1 Wednesday that a school district in Pennsylvania violated the First Amendment by punishing a cheerleader who used expletives in a Snapchat post while off campus.

Why it matters: The case pushed the boundaries of students' First Amendment rights and what schools can enforce outside school grounds, especially in the digital age.

Driving the news: The Court held that, "while public schools may have a special interest in regulating some off-campus student speech, the special interests offered by the school are not sufficient to overcome [the student’s] interest in free expression in this case."

• The ruling was written by Justice Stephen Breyer and only Justice Clarence Thomas dissented.

Catch up quick: When Brandi Levy, a Pennsylvania freshman, did not make the varsity cheerleading squad for her high school, she posted a vulgar message on Snapchat saying, "F school, F cheer, F softball, F everything,'" per ABC News.

• The school caught wind of Levy's message and suspended her from the team for a year, saying the punishment was necessary to "avoid chaos" and ensure a "teamlike environment," per The New York Times.

Flashback: In the landmark First Amendment case, Tinker v. Des Moines Independent Community School District in 1969, the Supreme Court allowed students protesting the Vietnam War to wear black armbands, saying the students did not “shed their constitutional rights to freedom of speech or expression at the schoolhouse gate,” per the New York Times.

• The Supreme Court has limited students' First Amendment rights on school grounds since Tinker v. Des Moines, per NYT.