seeking to invoke the exception must establish that they agreed to engage in a joint effort and to keep the shared information confidential from outsiders. See, e.g., United States v. Schwimmer, 892 F.2d 237, 243-44 (2d Cir.1989) (finding valid joint defense privilege where information was “imparted in confidence” between parties “who had agreed upon and undertaken a joint strategy”); United States v. Sawyer, 878 F.Supp. 295, 297 (D.Mass.1995) (despite similar interests between employer and employee, insufficient evidence that communications were made during the course of a joint defense effort; proponent could neither establish time frame of agreement nor acts creating and/or terminating the agreement); United States v. United Tech. Corp., 979 F.Supp. 108, 110, 112 (D.Conn.1997) (<HOLDING>); Libbey Glass, Inc. v. Oneida, Ltd., 197
holding common interest doctrine shielded information consortium members shared pursuant to collaboration agreement recognizing doctrine recognizing that tribes and states understood that they shared the right to manage the exercise of in common hunting and fishing rights recognizing a subset of the common interest privilege as parents and schools have a corresponding interest in the free flow of information about administrators and faculty members holding that there was no waiver of the work product protection because the business and public relations firm specializing in litigationrelated crisis management shared a common interest