Public schools are not allowed to forbid students' right to freedom of speech, unless it disrupts education. But that wasn't necessarily true until a court case from Iowa made its way to the Supreme Court back in the 60s. John Tinker was behind the case, known as Tinker v. Des Moines. He and other students went to school wearing black arm bands to protest the Vietnam War. They were kicked out and told not to come back to class unless they removed the bands and the rest as they say, is history.