https://www.theguardian.com/technology/2019/apr/01/why-am-i-seeing-this-new-facebook-tool-to-demystify-news-feed

Facebook aims to assure users it’s not spying on them via their phone’s mic for better ads

Facebook is attempting to demystify how its news feed works with a new feature that explains to users how it picks the posts and adverts to show them.