Facebook had to change its newsfeed because some people were using it like email

A small subset of Facebook users, though, had been treating Facebook's newsfeed more like an email inbox - a problem when it comes to the way the social network decides to show you stories.

In a deep dive by Slate's Will Oremus into who controls your feed, Facebook engineers told Slate that a large part of how Facebook knows what to show you is based on the actions you take while on the site. This can range from how long you look at a story or whether you like the post before or after reading it, the latter signaling you read the post and were more interested in it, according to Slate.

If a story is annoying or bothersome, some users will go as far as to click the little grey triangle on the top right of each story and click to "Hide" the offending post.

Facebook normally takes that to mean that it should show you less of those stories - whether you're hiding clickbait or a friend's baby photos.

But when looking at the data, Facebook soon found that some of its users interpreted that "hide" button like the delete or archive button in your email inbox. Every story they read they would then "hide" - a signal that confused Facebook's algorithm, which interpreted it as though the person hated everything they read.

As Slate's Will Oremus explains:

"Facebook's data scientists were aware that a small proportion of users-5 percent-were doing 85 percent of the hiding. When Facebook dug deeper, it found that a small subset of those 5 percent were hiding almost every story they saw-even ones they had liked and commented on. For these "superhiders," it turned out, hiding a story didn't mean they disliked it; it was simply their way of marking the post "read," like archiving a message in Gmail."

Normally, Facebook doesn't make custom tweaks for users, but the "superhiders" were an exception. In July, Facebook engineer Sami Tas tweaked the newsfeed algorithm. The blog post explaining the change went relatively unnoticed, but for those who were treating their Facebook feed like an inbox, "hiding" a story no longer means that you don't want to see it.