In an effort to prove that it can be almost as menacing as China, Iran has apparently hacked a bunch of US energy companies.
The Wall Street Journal claims the hackers were able to access control system software in several oil, gas and power companies. US officials compared the attacks to cyber reconnaissance missions. They believe the small scale attacks could be used to figure out how to disrupt services in the future. Basically, in case of war, it's alleged that Iran could target US infrastructure, and if it fails it can block the Strait of Hormuz.
In theory, attacks on control systems could also inflict crippling physical damage. One example would be turning off safety features, such as automatic lubrication of generators and other equipment.
This isn’t the first time the US has accused Iran of cyber attacks. Iran has allegedly targeted US banks with massive DoS attacks in the past and it is said to be aggressively expanding its cyber warfare capabilities. Iran apparently started taking cyber warfare a bit more seriously after it was struck by the Stuxnet virus.
If we're not mistaken, this is what the intelligence community would call blowback.