Facebook recently noticed some strange things happening to their website in Tunisia such as political-protest pages were being hacked and users complaining someone logged into their Facebook accounts deleted them. After lot of investigation, the Facebook security team took two measures in order to overcome these issues:
First, Facebook routed all requests to their website from Tunisia to an https server, ensuring all information gets encrypted and becomes un-susceptible to keylogging.
Second, Facebook started posing questions (like mother’s maiden name) to any user who had logged out and then logged back in during the time when the malicious code was running.