Facebook has added a new security feature, Login Approvals, to provide improved security for its members. A one-time numeric code is needed with the username and password when logging on Facebook from other devices which have yet to be approved.
Facebook has recently announced a new feature to tighten their security and helped users prevent unauthorized access to their accounts. "Login Approvals" requires the user to key in a one-time code (which is sent to his mobile phone) with his or her username and password when logging in from an unrecognized computer or device. In this way, it helps to protect against unauthorized access from people who have hacked or stolen the username and password. The user would be locked out from the account until he logs in using an approved device or computer.
The social media company is also considering other technologies to be incorporated to Login Approvals besides SMS.
Source: PC World