Scott, J. (1990). A Matter of Record: Documentary Sources in Social Research. Cambridge: Polity Press.
In this work, John Scott explores all sorts of public and private records with the intent of helping researchers understand how best to extract usable information from them. This is a how-to book, but also examines social and ethical issues connected with documents.
One ethical examination comes in a series of chapters examining private documents, the intent of their creation, and in what ways a researcher should approach private documents. Some examples include wills, private journals, or letters written for consumption only by the addressee. Does the passage of time make these documents less privileged? What if any of these are pulled into the public sphere in a court dispute or if the author becomes a public figure by running for political office?
Much of the book is a sort of nuts-and-bolts approach to finding data that matter to the particular focus of the research. For example, health records might be pertinent when looking for concentrations of a particular illness. Health records are private, in particular recent information that is subject to modern HIPAA rules. Access may be limited and the specific way such data can be used through anonymizing is also controlled through various research rules.
For those who seek information that relate to sociological trends or influences, digging through public and private records is inevitable. One example of such research is in the field of family history. Many people are engaged in that research for personal reasons, but once it is published in an academic work or on publicly accessible websites, there are laws and ethical concerns that take effect. John Scott has examined the ins-and-outs in this work about academic use of records.