Defence Secretary dubs 'cyber warfare' US' biggest security threat

US Defence Secretary Leon Panetta has cited cyber warfare as the biggest security threat because it can severely hit the country’s financial system.He also stressed the need for the US to develop technology to defend itself against cyber attacks.“I think we have to be prepared not only to defend against that kind of attack but if necessary we are going to have to be prepared to be able to be aggressive when it comes to cyber efforts as well. We've got to develop the technology, the capability, we've got to be able to defend this country,” CBS News quoted Panetta, as saying.Panetta pointed out that countries across the world use the Internet for accessing information but China uses it as a means to access information in the business arena.He said that any move, which adversely affects the country or hits a major grid system, also raises a question whether it constitutes an act of war.