(1) http://www.guardian.co.uk/world/2011/may/31/washington-moves...
(1) http://www.guardian.co.uk/world/2011/may/31/washington-moves...
It's CNA (e.g. operations designed specifically to disrupt or destroy civilian or military targets) which is "on the table" for act-of-war status, particularly if there is kinetic effect. An example would be if something like Stuxnet were deployed against the U.S. power grid.
The idea is that it doesn't matter whether a power plant was disabled via a bomb or a backdoor. Both the intent and the outcome are the same. So the declaration of policy you linked to is really a clarification rather than a "change of course".
The lines are blurry when it comes to CNE and critical infrastructure. The problem you have is that if, say, 3 competing agencies are all vying for control of the same powerplant for CNE reasons (e.g. not trying to cause damage), the plant might nonetheless get taken out by accident. I'm not sure anyone is clear on what to do in that kind of a situation.
[1] We can divide "cyber" operations into the following categories (straight from wikipedia):
* Computer Network Attack (CNA): Includes actions taken via computer networks to disrupt, deny, degrade, or destroy the information within computers and computer networks and/or the computers/networks themselves.
* Computer Network Defense (CND): Includes actions taken via computer networks to protect, monitor, analyze, detect and respond to network attacks, intrusions, disruptions or other unauthorized actions that would compromise or cripple defense information systems and networks. Joint Pub 6.0 further outlines Computer Network Defense as an aspect of NetOps
* Computer Network Exploitation (CNE): Includes enabling actions and intelligence collection via computer networks that exploit data gathered from target or enemy information systems or networks.
Same applies to lower level stuff. If there is say a hypothetical an irrational policy for mandatory arrest of anyone suspected of terrorism, one shouldn't be surprised that neighbors will start reporting each other over the color of fence or wrong type of shutters installed.
I guess they couldn't just say "you hack us, we hack you back". Or more realistically: "We hack you first in secret. Then you hack us back in secret. And then we have an excuse to go public to get the public's support to hack you back, and get more funding and bills passed for whatever other secret operations we want to do next". Case in point: Iran.