Facebook continues to enhance security features it seems on an ever more frequent basis. Per their stats, the improvements are working and reducing issues. It's a monumental effort including stopping over 600,000 compromised logins per day! The security features aren't simple though. It appears that Facebook recognized how complex their security features are so they subsequently published this Facebook Security infographic.
At Facebook, we take the privacy and safety of the people who use our site very seriously. Using a combination of technological innovations such as database checks and roadblocks, as well as our dedicated staff, we're working 24/7 to ensure everyone's information is safe and secure.