Washington Post 
April 8, 2011
The Department of Homeland Security is planning to tap social networks such as Facebook and Twitter to help spread the word in the event of a terror attack, the Associated Press reported Thursday .
In a draft of a plan obtained by AP, DHS says it may turn to social networks to spread news about new terror alerts “when appropriate,” after notifying local, state and federal officials.
The plan is expected to go into effect on April 27 and will replace the government’s current color-coded rubric with a two-tier warning system. “Elevated” alerts would be issued when there is a credible threat against the United States. An “imminent alert” would indicated a credible, specific and impending terrorist threat or on-going attack. According to the draft, each warning would have an expiration date.