It wasn’t too long ago that preparing for the breakdown of civilization was the obsession of fringe groups on the margins of society—cult members waiting for the rapture or white supremacists bracing for a race war.

According to a new report in the New Yorker (paywall), a growing number of Silicon Valley entrepreneurs and other wealthy individuals across the US are joining in. Many fear that extreme inequality may trigger civil unrest, and are planning for the collapse of law and order. They’re doing everything from stocking up on gold coins and canned foods, to buying land on remote islands and building bunkers. Among other things:

Steve Huffman, the CEO of Reddit, had laser eye surgery after he realized finding eye glasses could be a major problem if society descends into chaos

Marvin Liao, a partner at a venture-capital firm, bought weapons and began taking archery classes.

Antonio Garcia Martinez, a former Facebook executive, bought five remote acres on an island and equipped it with generators and thousands of rounds of ammunition

New Zealand, according to LinkedIn co-founder Reid Hoffman, is the favored refuge of the tech elite in the event of a disaster. It’s called “apocalypse insurance”

Preparing for the end of the world is not new, and at times even made sense. At the height of the Cold War, president John F. Kennedy encouraged Americans to build bomb shelters. But as the Cold War ended, worrying about the end times became a fringe obsession. There was a brief resurgence in 1999 as panic over computers not being properly programmed for the rollover to 2000 became widespread. Ironically, 17 years ago it was the elite who reassured the world that technology could fix the problem.

This time, however, it’s our growing dependence on technology that is helping to drive the worry. “Our food supply is dependent on GPS, logistics, and weather forecasting,” one CEO told the magazine, “and those systems are generally dependent on the Internet.”

From the outside, much of this looks like the rich indulging in fantasy, perhaps after seeing the latest Mad Max installment. A doomsday plan is one more toy to buy once you’ve bought everything else. For the rest of us, who won’t be able to flee to the hills, the best way to prepare for the end of civilization is to work hard to make sure it never comes.