Vernor Vinge's A Deepness in the Sky depicts a human interstellar civilization thousands of years in the future, in which superluminal travel is impossible (for

Vernor Vinge's A Deepness in the Sky depicts a human interstellar civilization thousands of years in the future, in which superluminal travel is impossible (for the humans), so travelers use hibernation to pass the decades while their ships travel between star systems. Merchants often revisit systems after a century or two, so see great changes in each visit. The merchants repeatedly find that once smart dust (tiny swarms of nanomachines) are developed, governments inevitably use them for ubiquitous surveillance, which inevitably causes societal collapse. <https://blog.regehr.org/archives/255 https://blog.regehr.org/archives/255>