Forgot to logout from somewhere! Do you want to logout from logged in devices you logged in yourself but now thinking of someone else may be using it! Well, Facebook has the facility to help you get detail about logged in devices and logout from those places if you wish so.
It may happen that you logged in from a friend device or you may be checking something on friend's PC while taking to him and you are now concerned whether all your information is accessible to other people or not! If you logged-in from public place or cyber café then your concern is serious. Other can take out your private information without your permission. Just rush to your Laptop and check from where (which devices) and when your account is being accessed. You can discontinue the activity if you wish so. If you see any unknown device you never logged in yourself then first End the activity from there and change password and take other important security measures you should do to secure your account.
Head toward Account Settings → Security.
Click on the Active Sessions and you will see all your logged-in device with useful information listed with date.
You may like to browse few more posts on Facebook security issue.