Widespread fears about the future — including concerns about politics, the economy, the environment and all-out nuclear war — have led some people to prepare for ways to defend themselves. The “survivalists” include some Silicon Valley executives, who worry about the tech future they have helped to create.
http://www.npr.org/2017/01/25/511507434/why-some-silicon-valley-tech-executives-are-bunkering-down-for-doomsday
Not that bad of an idea.