When FBI featurs social meida, you know that it has become mainstream. The first article in the July, 2010 issue of FBI Law Enforcement Bulletin carries the title The Public Information Officer and Today’s Digital News Environment. The author, a former police lieutenant, states that "...PIOs must continue to embrace technology and its benefits or risk becoming obsolete." The article goes on to list several tools: RSS feed, Twitter, Nixle, YouTube, and facebook, but Nixle is the one receiving a lot of attention. With a good reason: It is a secure and identity-certified communication service that allows local, county and state law enforcement and government agencies to connect with local residents over cell phone, email and web. One can limit information received by zip code.
However, one should read carefully Nixle's Terms of Service before signing up: there is a paragraph on their restrictions on linking (i.e. no deep linking) and framing activities. Caching is also not allowed. To see its Terms of Service, go to its homepage, click the button "Start receiving alerts today". I am not going to deep-link it here for you.
26 minutes ago