At the bottom of the ocean floor rest the cables that make the Internet possible. Strange though it may seem, the world is strung together like a gigantic submarine zither. Optical fiber pipes—the plucked strings of the Internet—carry our music, our chatter, our data across the globe.

One can understand why American defense officials might be worried then, that a Russian spy ship has been snooping around these wired routes. As a New York Times article earlier this week suggested, one cannot rule out the possibility of a devastating attack against these vital lines—”the ultimate Russian hack on the United States,” if you will. The Pentagon, for one, has certainly contemplated such a doomsday event.

Should the rest of us be concerned? I asked Doug Madory, director of Internet analysis at Dyn, which keeps close tabs on the performance of Internet infrastructure, for his thoughts. He maintains that these networks—though they suffer cable breaks somewhat regularly (especially in shallow, anchor-prone waters)—are phenomenally resilient. A concerted attack, however, might pose a bigger problem.

“If someone did sever cables in the most extreme Hollywood scenario,” he said, “any kind of international commerce or communications could be severely impacted.” Still the greatest impact, he suggested, might be psychological.

“It does sound a little James Bond,” he added. “But I guess that’s what the Navy is paid to defend against.”

Such telecom attacks have a precedent—if not yet at the scale imagine by the Times. A spate of mysterious cable cuts hit California this year. Saboteurs in Gabon recently sliced submarine wires amid a labor dispute. And the Egyptian Navy arrested divers who damaged undersea lines with explosives while apparently scavenging for scrap metal in 2013. Madory describes these events and others in a blog post of his own here.

I mulled these incidents and incursions while visiting AT&T’s T global network operations center earlier this week. (More on that to come.) There I had a birds-eye view of the company’s webwork of wired and wireless links—as well as a squid’s-eye view of its undersea cable system. That submarine network appeared on screen as a tangled ball of seaweed, shaded an algal green.

“I swear I didn’t set that up,” the tour guide told me, grinning as he motioned toward the display. There was not a jot of red to be found. (Green means “good” connection; red means “problem.”) At least for now, I presume, the network must be doing okay.

So there’s your Oct. 31, technologic apocalypse scenario. Happy Halloween, dear readers.

A version of this post originally appeared in Data Sheet, Fortune’s daily tech-business newsletter. Subscribe here.

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