"A communications system and IT infrastructure used by [DHS] to transmit sensitive but unclassified information. The HSIN serves as a nationwide information-sharing and collaboration tool and is intended to offer realtime chat and instant messaging capability as well as a document library that contains reports from multiple Federal, State, and local sources. HSIN features suspicious incident information and analysis of terrorist threats, tactics, and weapons. HSIN includes over 35 communities of interest, such as emergency management, law enforcement, counterterrorism, States, and private sector communities. Each community of interest has Web pages that are tailored for the community and contain general and community-specific news articles, links, and contact information. HSIN features include a document library, a discussion thread/bulletin board capability, and a chat tool among others". (HSC, NCPIP, August 2007, p. 63)