The Supreme Court of the United States, in a unanimous decision, has held that the control group test for determining the applicability of the attorney-client privilege in the corporate context is overly restrictive and that any future application of the privilege must be on a case by case basis. The Court also held that the work product doctrine is applicable to administrative summonses.
Upjohn Co. v. United States, 449 U.S. 383 (1981).
Dolores J. Krawec,
Attorney-Client Privilege - Corporations - Work Product Doctrine - Administrative Summonses,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol20/iss2/7