Legal Question in Technology Law in South Dakota

Sure. The school is only regulating what you can do with its computer, not what you can do on your own time. You will still be free to visit other sites with your own computer or someone else's. But you do not have the right to use the school's equipment however you choose.

One key determinant is whether your school is a private school or public school. Private schools will have a bit more freedom to censor you. A public high school, as a government entity, is subject to the First Amendment's limitation against government suppression of speech. While courts have allowed for some forms of censorship to facilitate the public school's education mission, the facts you set out suggest that the school may have exceeeded those limits by abridging your freedom of speech beyond the school's educational interests. If this is a public high school, I suggest that you contact your local ACLU (try http://www.aclusd.org/) or the Student Press Law Center (http://www.splc.org/) to discuss your particular situation.