An "Undark Age": Societal collapse due to overabundance and overcomplexity of information.

There are a couple of scenarios exploring this idea somewhat in sci fi, either advanced technology from an alien source enabling terrorists and dissidents to attack and destroy the government and the rule of law collapses afterwards as there is nobody left to enforce it, the new rulers actually don't want to bother and find it easier to control the masses. Another is the typical technology runaway and there are plenty examples with AI diverging interest from humanity or more simple nano bots turning every piece of matter into their own copies without an overarching, high level intelligence. Then there are the less likely and more wishful ideas like time travel altering the past with dire consequences for the present and the future.

/r/Futurology Thread