In Peter Watts' Maelstrom (2002) it's ultimately self replicating code that pushes the internet from a brutal and rough and competitive infoscape into something worse & even more rawly aggressive. But the book and it's tattered wasteland of the internet still has such tone setting power for me, set such an image up of an internet after humans: where the competing forces of exploitation have degraded and degraded and degraded the situation, pushing humans out.

Recently revisited on Peter's blog: https://www.rifters.com/crawl/?p=11220