the principal, for purpose of waiver of the privilege. *762 David P. Durbin, D. Stephenson Schwinn, Jordan Coyne and Savits LLP, Washington, DC, Arthur J. Mccolgan, II, Ryan M. Henderson, Walker Wilcox Mat- ousek LLP, Chicago, IL, for Plaintiffs. Michael Thomas Sharkey, Andrew M. Weiner, Dickstein Shapiro LLP