The first time I heard “dark factories”, I pictured the orcs toiling underground at Isengard (that’s Lord of the Rings for any readers who are not the right type of nerd to know that). I also think of Philip K. Dick’s story Autofac, one of my all time favorites. But no, the idea is that factories are emerging in China that are so automated that the lights don’t need to be on most of the time, because no humans are present. Naked Capitalism has a ton of links describing this phenomenon in China. Apparently U.S. industrialists are touring these Chinese factories and are shocked at how advanced they are and how far behind they (i.e., western industry) are.
The fact that western industrialists are invited to tour these factories would suggest that the technology is not secret. So maybe we should not feel threatened but rather look for opportunities to partner and learn. No doubt, there are similar factories churning out military and security hardware that are secret.