In these uncertain times, it seems that preparing for the apocalypse is no longer a unique activity of the overly paranoid. According to an essay in the New Yorker, a large number of Silicon Valley leaders are taking action to ready themselves for the end of civilization.

LinkedIn cofounder and venture capitalist Reid Hoffman estimates that more than 50 percent of tech industry billionaires have bought some form of "apocalypse insurance," such as fortified underground bunkers built to withstand nuclear, chemical, and biological attacks.

But it's not just a third world war that the super rich fear. Many, including Peter Thiel, are concerned about civil unrest in the US brought about by anything from economic meltdown, to earthquakes, to riots. As such, billionaires are buying land in New Zealand as a getaway in case things in the States get out of hand.

Roughly 1350 square miles of New Zealand land was purchased by people from outside of the country in the first ten months of 2016. Thiel has even been granted citizenship, according to the New Zealand Herald. "Saying you're 'buying a house in New Zealand' is kind of a wink, wink, say no more," said Hoffman.

Another CEO survivalist is Reddit CEO and cofounder Steve Huffman, who underwent laser eye surgery in 2015 to improve his odds of surviving if everything goes a bit Mad Max. "If the world ends --- and not even if the world ends, but if we have trouble --- getting contacts or glasses is going to be a huge pain in the ass," Huffman said. "I own a couple of motorcycles. I have a bunch of guns and ammo. Food. I figure that, with that, I can hole up in my house for some amount of time," he added.

It's a similar story among other current and former company execs and bosses. One-time Yahoo executive Marvin Liao started taking archery classes and bought weapons, while former Facebook exec Antonio Garcia Martinez has purchased five acres of woodland on an island in the Pacific Northwest, which he stocks with generators, solar panels, and ammo.

There's been something of a backlash to news of the apocalypse plans. PayPal founder Max Levchin said the billionaires have a sense that they are "superior giants who move the needle and, even if it's [their] own failure, must be spared."

"I typically ask people, 'So you're worried about the pitchforks. How much money have you donated to your local homeless shelter?' " Levchin added.