On April 20, Secretary of Homeland Security Janet Napolitano announced that U.S. Department of Homeland Security (DHS) has put in place a new National Terrorism Advisory System (NTAS), replacing the color-coded system that had been used since 2002. NTAS has two threat levels: "Elevated Threat," which warns of a credible terrorist threat against the United States, and "Imminent Threat," which warns of a credible, specific and impending terrorist threat against the United States. Depending on the nature of the threat, alerts may be sent to law enforcement, distributed to affected areas of the private sector, or issued to the public through official and social media channels. For more information on the National Terrorism Advisory System or to receive NTAS alerts, visit www.dhs.gov/alerts.