Censorship in Schools

The question I am asking is: When we practice censorship in schools, are we protecting our students, or hurting them by limiting their exposure to certain things? Censorship can be practiced in many ways. In school it can include the banning of books, dress codes, or the withholding of ideals and information. If a book gets banned or an ideal dismissed, that then poses the question of why. If a student cannot get the answer, it could make him or her inclined to try to figure it out on their own. So should we be more concerned about trying to keep the information away from students, or is it possible to discuss objectionable material in groups and present it in a respectable manner? Dress codes imply that a general conformity is desired. Certain styles of dress are offensive to different people so if everyone in a school dresses somewhat the same there is less room to discriminate. But this is done at the cost of a person's individuality. If we say someone has to dress a certain way then we limit their expression of who they are. So, is there more potential harm if we do not practice censorship, or is it ultimately a negative aspect of school systems today?