0 If you want to know that your Facebook account has been hacked then follow these steps: 1. Log in to your account then 2. go to settings then 3. There is a security tab click on it then 4. you`ll see Active sessions tab click on edit there 5. if you see more than one session then there could be a possibility that your account has been hacked what to if your account has been hacked simple 6. just click on end all active session button you`ll be logged out of every device where your account is online.