Want to know if someone is logged into your Facebook account without your permission? First, go to your settings page. Under the Security folder, youll see the link "Where Youre Logged In." Here you will find all your active Facebook log-ins from both desktop or mobile. It will (usually) provide data on the location, browser, and device. If something seems fishy, you also have the ability to "end activity" from individual or all devices.
This also comes in handy if you logged in to your friends computer or on some public laptop, but forgot to log out.
