Even now, people who use Facebook regularly have their exposure to information mediated through News Feed algorithms that seem fairly opaque. Of course, you can

Even now, people who use Facebook regularly have their exposure to information mediated through News Feed algorithms that seem fairly opaque. Of course, you can take manual actions to "shape" your feed, but mostly it's computers deciding who you'd probably like to hear from, and maybe even what you'd like to hear about. It's interesting how such a major part of people's infostreams are invisibly shaped by behavior-trained systems.