Facebook stores all your searches for people in your Activity Log.
Last week, we noticed that Facebook has been storing all our past searches in our Activity Log. You can see this if you set your log to "Only Me" visibility. Your searches won't ever display on your timeline or profile, but there's something inherently icky about having them saved in your account at all. They're just lurking in the shadows, beating away like the telltale heart of our creepy stalker selves.
It seemed that you could only delete your past activity line by line, but a BuzzFeed commenter noted that there IS indeed a way to clear all your searches all at once.
Here's how to do it. You'll rest easier. Deep breath.