But Facebook already displays posts based on an algorithm; it doesn't do it chronologically, and it's actually almost impossible for me to find a specific post

But Facebook already displays posts based on an algorithm; it doesn't do it chronologically, and it's actually almost impossible for me to find a specific post in my timeline. Especially from the mobile site, it's very common that I see something in the moment between opening the app and my timeline updating, and never being able to see the update again. Facebook is already making the decision as to whether to show you a post or not, and they make that decision based on what they think you will want to see and what you will engage with, all of which is fuzzy and subjective. They already manipulate things you see to encourage engagement; for example, if their algorithm shows that your engagement is dropping and you're about to leave, they'll show other people your profile and say 'do you know this person?', because someone adding you as a friend boosts your engagement. So if you think that showing you posts which are happy or sad is manipulative, be aware that Facebook is already filtering your potential-friends list and showing you people solely to boost engagement (either yours or theirs). Looked at another way, this means that it's possible their algorithm isn't currently showing you people you might know because it's not as beneficial for them to make that connection for you yet. So the purpose of Facebook's site is to get people to interact and generate behaviour, and now they're experimenting with that; which posts do we show? which do we hide? They haven't shown them all for ages, so this is just a tweak to their algorithm that they were testing. What's really interesting here is how this could actually be used for good. Someone feeling crappy? Show them fewer negative posts and more positive posts. Maybe that will help. Show negative posts less often, and make society in general a little more positive.