The Container Security Initiative (CSI) a.k.a. the 24-Hour Rule[not verified in body] was launched in 2002 by the U.S. Bureau of Customs and Border Protection (CBP), an agency of the Department of Homeland Security.[1] Its purpose was to increase security for container cargo shipped to the United States. As the CBP puts it, the intent is to "extend [the] zone of security outward so that American borders are the last line of defense, not the first."[2]