Lot of facebook users forget to uncheck ‘remember me’ option when they login from public or friends computers. This leads to easy exposure of their login details to not so good people. That is why Facebook has this feature using which you can get a alert when someone else logged in your facebook account, and that’s the time you should change your password. If you think someone else is using your facebook account follow these simple steps to turn on login notification.
Note: Make sure you have you have your mobile number registered with facebook before following these steps. Go to facebook.com/settings?tab=mobile for that
> Open facebook.com/settings?tab=security§ion=notifications&t and Check the email and SMS option. Save changes and logout.
Now login again and facebook would as you to name your device. Name it and check ‘never ask me again’. This makes facebook to recognize you device as a safe one to login.
If you get any alert go to facebook.com/settings?tab=security§ion=sessions&t and click ‘end session’ on suspicious session. and change your password immediately.Lets Hope you never have to do that. Have Fun!!