An important problem facing large, distributed organizations is the efficient management and distribution of information, knowledge, and expertise. In this paper we present the design and implementation of a low-cost, extensible, flexible, and dynamic peer-to-peer (P2P) knowledge network that helps address this problem. This system, known as Shock, is designed to protect the privacy of user’s personal information, such as email, web browsing habits, etc., while making that information available for knowledge management applications. It reduces participation costs for such applications as expert-finding, allows highly targeted messaging, and enables novel kinds of ad hoc conversation and anonymous messaging. The system is tightly integrated with users’ email clients, taking advantage of email as habitat.