Facebook has introduced a way that if someone steals your password, it will restrict that stolen password and will aware you by notifying that your password is owned by hackers.
Facebook is working on this new system after the massive hack of “Adobe Passwords” that password hacking can cause serious significances in the form of personal data theft, now onward Facebook is working on to minimize such happenings and build such system which is exclusively devoted to protect peoples Facebook accounts. In this system Facebook collects the stolen identifications that are publicly displayed and evaluate those using special analytics to see whether the combination of stolen email or password matches with the one that is used on Facebook. In case it finds a match, the Facebook will inform you as you login your account and will guide you through a technique of changing your password.
This is completely an automatic process, said Chris Long, Security Engineer at Facebook, In order to make your account safer, allowed the Login Approvals for additional security, due to which you will need to enter a security code from your phone when logging in from a new browser.
So Facebook assure you and safe you, so dont worry if your password gets hacked.