The ADL maintains a Visual Database of Extremist Symbols, Logos and Tattoos on the Law Enforcement Agency Resource Network. It is an Open Source (OSINT) webpage. The ADL also has several webpages devoted to officer safety as it relates to extremist groups. You can browse the database and locate other training materials at:
http://www.adl.org/hate_symbols/default.asp

Additionally, I teach two LEO related courses at Cal State Fullerton. In both classes we explored hate crime as it relates to the web. As part of their assignment the students are posting in an OSINT threaded discussion on the Criminal Justice Online forum at
http://www.criminaljustice-online.com/forum8/181.html.

You might find that discussion interesting. Note that it is taking place in the forum area devoted to “Terrorism and Criminal Justice.” While our national efforts seem to be focused abroad there is certainly potential here at home.

Raymond
www.hitechcj.com