But this first impression would be wrong. Librarians deal with people every day. They hold information about these people, and have a responsibility to handle the information properly. Librarians may also be called on to advise their colleagues on matters relating to information-handling. Data Protection could clearly come under this heading.
And librarians are clearly Data Subjects in their own right, so have an interest in knowing that their own data, and that of their colleagues, is being treated in the appropriate way.