The following are some additional sources found while researching this topic.

Abioye, A. (2010). Confidentiality and Protection of Official Records in the Freedom of Information Era: Nigeria’s Situation. African Journal Of Library, Archives & Information Science, 20(1), 29-39.
A look at another country’s issues of confidentiality and libraries.

Adams, H. R. (2002). Privacy & Confidentiality. American Libraries, 33(10), 44.
Focused on youths and their privacy needs.

Bowers, S. L. (2006). Privacy and Library Records. Journal Of Academic Librarianship, 32(4), 377-383.
History of the issue of privacy and library records (as up to that year, of course).

Carson, B. b., Strauch, B. s., & Montgomery, J. j. (2004). Legally Speaking — Tarisoff, Patron Confidentiality, and Duty to Society: An Ethical Quandary. Against The Grain, 16(3), 76-79.
Good look at the ethical issues surrounding privacy and confidentiality.

Harger, E. (2014). Abandoning Snowden… and Privacy?. Progressive Librarian, (42), 10-60.
Criticism of the ALA’s withdrawal from support of Snowden’s status as a whistleblower.

Jackman, R. C., & Kegel, M. J. (2004). Louisiana Libraries and the USA Patriot Act: The Need for Confidentiality Policies. Louisiana Libraries, 67(1), 3-11.
Addresses the gap in policies that protect patron confidentiality in Louisiana.

Kolkmeier, K. (2007). Emergency Exception to the Illinois Library Records Confidentiality Act. ILA Reporter, 25(5), 8-12.
Overview of a new policy that allows law enforcement to access records without a court order.

Million, A. C., & Fisher, K. 1. (1986). Library records: a review of confidentiality laws and policies. Journal Of Academic Librarianship, 11346-349.
Interesting look back at issues from the early days of electronic records-keeping.

Munyoro, I. m. (2017). Issues of confidentiality and public interest: A case study from a library perspective. Mousaion, 35(3), 1-17.
Good case study from Zimbabwe, for some interesting perspective.

Nelson, J. A. (2002). Balancing Our Right to Know with an Individual’s Right to Privacy: Confidentiality of Library Patron Records in Kentucky. Kentucky Libraries, 66(4), 20-25.
Early post-PATRIOT Act article on the danger of allowing right to privacy to slip away.

Neuhaus, P., Van Fleet, C., & Wallace, D. P. (2003). Privacy and Confidentiality in Digital Reference. Reference & User Services Quarterly, 43(1), 26-36.
A perspective from the reference side of things.

Privacy & confidentiality in libraries. (2002). ILA Reporter, 20(4), 1-16.
Good in-depth analysis of the post-PATRIOT Act impact on privacy and confidentiality in libraries.

Seaman, S. (2000). Confidentiality of library circulation records. Colorado Libraries, 26(2), 32-35.
A perspective from the circulation side of things.

Walker, S. (2008). Half of Vermont Academic and Public Libraries Lack Written Confidentiality Policies Despite Directors’ Support for Principles of Patron Confidentiality. Evidence Based Library & Information Practice, 3(3), 68-72.
Addresses the issue of gaps in privacy policies in a post-Patriot Act era.