The first amendment according to the constitution is stated as "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances." TLDR your opinions or the press can't be censored by the government.
In this court case, a high school student was talking bad about faculty members in a blog post criticizing their handling of the schools "Jamfest". He also used offensive language in the blog post. This student used t-shirt sales to petition a change in the handling in the event, but students were prohibited from wearing the shirts
The school one the case due to the students case being "false and misleading."
I personally think this case is against the first amendment this blocks this students right to freedom of speech.