[white-flame]

I don't even have a Facebook account. But with my relatives that do, this stuff leaks in from seeing their coworkers' & acquaintances' posts and escalates over time once there's even the slightest hook with the algorithm. Any reasonable political opinion they might have in thumbs-upping some innocuous content eventually routes into the algo feeding more extremist content.

Most people don't outright block offtopic material, they just gloss over it, and it still ends up with influence because that's what Facebook optimizes for. Plus people will still take the occasional click of curiosity to see what some posts are all about, even if they're not really into that content.

Yes, if you do have the discipline to take a zero-tolerance personal policy and immediately block even inoffensive things that just touch into the realm of polarizing, you can probably keep your feeds clean. But most people (eg, non-HN types) don't understand what Facebook is doing and don't think to actively defend against it, and just absent-mindedly consume the feed with no click discipline.