Network security experts working for Canadian power companies have found evidence of hackers getting into company networks. In some cases, the security technicians have found programs hidden by hackers in the power company system. When these programs are dissected, it was found that some of them were designed to crash the power company computer system when commanded to do so.
Although power companies have increased their security, one of the major vulnerabilities has been the growing use of smart grids. This innovation uses smart (connected to the Internet) meters that keep the power company computers constantly aware of who is using how much electricity. This allows for variable pricing (lower prices when demand is low, and vice versa) and better monitoring of the entire network. This makes the networks more reliable, and lowers the cost of electricity for consumers.
But the smart grid is also more vulnerable to hackers. Since electricity grids are a military target, more than something an Internet crook would go after, the smart grid makes the power companies more vulnerable to hacking attacks. What has happened in Canada has also been seen in the United States, and other parts of the world. It is believed nations like China, or even Russia, are behind these hacker operations, if only to perfect their techniques. It's also possible that gangs of Internet criminals are being paid to plant these "service disruption bombs" in the form of hidden software that can be activated by the hackers to shut down, or even damage, electricity distribution networks and even the power plants.
The cheap solution, in the short run, is to abandon smart grid technologies and cut distribution networks and generating plants from any connections with the Internet. That makes these power operations more expensive to operate than those they stay with the new technologies. The other solution is to increase your security. But you never know if you are completely secure, so there is still some risk.