Ten labor unions representing 300,000 civilian employees of the U.S. Department of Defense filed a federal lawsuit yesterday against Defense Secretary Donald H. Rumsfeld, saying Rumsfeld's department violated the law by refusing to negotiate changes in its labor-management system. The suit, filed in U.S. District Court in Washington, comes after months of protests by the unions over proposals for a new National Security Personnel System, which Congress authorized for development in November 2003. The unions say the system, which seeks flexibility in hiring and assigning workers for security reasons, is using threats to security as a way to diminish the...