At a school-sanctioned and school-supervised event, a high school principal saw some of her students unfurl a large banner conveying a message she reasonably regarded as promoting illegal drug use. Consistent with established school policy prohibiting such messages at school events, the principal directed the students to take down the banner. One student— among those who had brought the banner to the event—refused to do so. The principal confiscated the banner and later suspended the student. The Ninth Circuit held that the principal's actions violated the First Amendment, and that the student could sue the principal for damages.