On January 13, 1981, the Supreme Court decided Upjohn Co. v. United States. Thirty-seven years later, it’s hard to think of a judicial decision that has had a more significant effect on internal investigations. The Court’s opinion made no mention of any particular warning procedure, instead focusing on the application of the attorney–client privilege to corporate clients. But it prompted the near-universal practice of lawyers who are conducting internal investigations advising corporate employees that they represent the company, rather than the employee, and that the company may waive the privilege at any time. There are countless articles highlighting the importance of providing the Upjohn warning while conducting internal investigations. I won’t rehash those points here. Instead I want to introduce a few fun factoids about the case itself, and the players involved in litigating it.