Twitter works best when you have a perfectly-curated follower list. For many, it's an evolving process as their interests and opinions -- and those of the people they follow -- slowly change. For years, Twitter has recommended "Who to Follow," but as Slate reports, the company is also testing the reverse. That's right, some users are seeing prompts about accounts they might want to unfollow. As a spokesperson explained to Slate: "We know that people want a relevant Twitter timeline. One way to do this is by unfollowing people they don't engage with regularly." It was an "incredibly limited test," however, that may never be rolled out widely.