http://www.bbc.com/news/world-32534923
On 7 December 1941, Japanese aircraft attacked the American naval base at Pearl Harbor, Hawaii. The attack was surprising, devastating, and drew the US into World War Two.
Sixty years later, US Defence Secretary Leon Panetta has warned of the risk of a "cyber-Pearl Harbor".
Is he right, or is the scale of the problem being overhyped? Four experts spoke to the BBC World Service Inquiry programme.