US Secretary of Defense, Leon Panetta, has earned of cybersecurity on Thursday during a speech that the agency is aware of foreign hackers that have remotely gained access to control systems for vital American infrastructure. Examples of this would be chemical, electricity and water plants.

Panetta stated:
We know that foreign cyber actors are probing America's critical infrastructure networks. We know of specific instances where intruders have successfully gained access to these control systems.
Panetta also warned of recent cyberattacks on US financial institutions have been "unprecedented" in both their scale, and speed. If you're a reader of our site, you might remember us reporting in August that the world's largest oil company, Saudi Aramco, were cyber-attacked.
I stated just afterwards with a follow-up post:
I still don't understand why oil and nuclear companies have their workstations Internet-capable. These systems should be the furthest away from any type of Internet connectivity, especially in the case of a "terrorist attack". Simply take down a few electricity, nuclear and other networks and the country would tear itself apart from the inside-out. Scary!
I still to this day don't understand why critical infrastructure is Internet-connected - the governments and companies of the world should know this, it's almost like they're just waiting for an attack on themselves. It would prove perfect for the financial industry if it were to happen, debt would be wiped and the problems would seemingly go away. Just like those missing $2 trillion on 9/11.