This issue of Library Technology Reports (vol. 55, no. 7), Protecting Privacy on Library Websites: Critical Technologies and Implementation Trends, explores the issues and technologies needed to deploy a library website with adequate protections for the privacy of those who visit. Without the implementation of standard encryption components, the online information-seeking activities of website visitors are vulnerable to exposure. Even when a site is properly encrypted, privacy can be circumvented through tracking agents placed on the site for analytics or advertising. Following discussion of the technical issues with implications for user privacy, this report includes the results of a broad study of the state of practice for these privacy-related technologies among public and academic libraries in the United States. This study reveals great progress among these libraries in the strengthening of privacy on their websites, though substantial gaps remain.