CBS Los Angeles reports that a recent report from the Brookings Institution, entitled "The Critical Infrastructure Gap: U.S. Port Facilities and Cyber Vulnerabilities," [PDF file] warns that a cyber disruption at the Port of Los Angeles or the Port of Long Beach could impact fully 20 percent of the U.S. maritime transportation system, costing the U.S. economy $1 billion every day the port isn't operating.

"In just a matter of days store shelves throughout the country would start to run empty, and the movement of 17 million Southern Californians, along with their economy, would be idled," U.S. Coast Guard Commander Joseph Kramek writes in the report.

Still, Kramek notes, the Port of Los Angeles has not conducted a cyber security vulnerability assessment, and doesn't have a cyber incident response plan.

"Like many other ports in this study, physical security is the primary focus of the security forces, and though many of its security and other systems rely on networked systems, cyber security is viewed as an IT function that lies outside the security portfolio," he writes.