The United States Computer Emergency Readiness Team (US-CERT), which is is the operational arm of the National Cyber Security Division (NCSD) at the Department of Homeland Security (DHS), which is charged with providing response support and defense against cyber attacks for the Federal Civil Executive Branch (.gov) and information sharing and collaboration with state and local government, industry and international partners.

The US-CERT allows people to reproduce and distribute documents found on its web site in whole or in part, as long as the text is not changed, the copyright statement or "produced by" statement is included, and the documents are used for noncommercial or internal purposes. There's a lot more to be found at the US-CERT web site, so if you're interested check it out at http://www.us-cert.gov/index.html.