Even more scary: You can tailor each individual's completely unique online universe to dovetail with the equally unique online universes of their IRL social connections / networks so that when they get together again at the holidays or meet for the first time at a bar they both frequent, they have serendipitous conversations about discovering the same hyper-niche thing recently, reinforcing their online conditioning with real-life anchoring.

This could be pervasive through not just online discussion forums, but also online news articles, auto-generated YouTube/TikTok feeds, pages inserted into search results that are custom generated on-demand, conversations on dating apps, etc.