>>509074453
At this point nothing but a reversion to 1970s information access (aka you have to go to the library to look stuff up), but in the near future maybe we also lose access to some military systems.
I don't think we'll lose control completely, remember that most of the US military still uses a custom version of Windows ME because they've embraced the engineering mantra of "do not interfere with a working system", because I doubt anything strategically important will be ever be set up without a human failsafe.