The recent decision of the U.S. Court of Appeals for the Sixth Circuit in In re FirstEnergy Corporation (Decision) reaffirmed the seminal 1981 decision in Upjohn Co. v. United States as the standard for maintaining assertions of privilege and work product protection in internal investigations. This second installment of a two-part article series analyzing the Decision examines how it may have impacted data breach investigations and offers best practices for good privilege hygiene, including insights from investigation experts on how to collect and preserve documents, conduct interviews and present findings to the client. The first part unpacked the procedural posture of the case and dissected the Decision to tease out its legal implications. See our two-part series on preserving the privilege for in-house counsel: “Communications and Common Issues” (Feb. 24, 2021), “Internal Investigations and Depositions” (Mar. 2, 2021).