Librarians´ ethics

Well, do you sometimes think: ´What for a silly question?´ - and then you have to remind yourself: There are no silly questions. What about ethics in librarianship? (Ethics is the scientific concentration of human's attitude and behaviour) Is it an important topic? Or is it already implied in todays librarians´ attitude?
In my opinion it is a crucial thing in reaching success in reference services. But its the very heart of the first law of a reference librarian: offering openness.