"I look at any vector of attack as troublesome," said Scott Aaronson, senior director of national security policy at the Edison Electric Institute, the association for all publicly traded electric companies.
"Given that you have all digital equipment helping to operate the grid … all threats are taken very seriously," Aaronson said in an interview. "But if you mandate a 10-foot wall, our adversaries will try to bring a 12-foot ladder."
However, he said that grid security has been on the industry's radar "for decades"—despite headlines that have only recently given the subject of technological breaches more attention.
"Our standards on cybersecurity were first drafted in 2007, before the urge to follow the shiniest object or Chicken Little with movie-script scenarios," he said.
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"We're making sure people get the right intelligence at the right time, and that threats are mitigated in near-real time," he said, even as he acknowledged utilities aren't "pretending we can protect everyone from everything."
Still, fears about U.S. energy security are becoming more than just abstract theories, or movie scenarios.
A widely circulated white paper by Symantec in June cited an "ongoing cyber-espionage campaign" against the energy sector by a shadowy hacker group known as Dragonfly. The report added that energy grid operators, utilities, oil and gas firms were at risk—not just domestically, but abroad as well. Additionally, others say the industry has far more work to do in the face of rapidly multiplying challenges to U.S. interests.
Utilities and regulators "are doing a lot, but there's more to be done," said one official with knowledge of the industry's cybersecurity efforts, who spoke to CNBC on the condition of anonymity.
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He said major population centers such as Washington, D.C., Los Angeles and New York City were always a big source of worry "not because of specific threats, but there's an elevated sense of a terrorist getting the biggest bang for the buck."
A grid hack "is certainly on people's radar, and it's a matter of how they address these risks internally," the official said. "It depends on what information you are getting, but nothing is being ignored, it's just a matter of how they prioritize it."
—By CNBC's Javier E. David