Facebook reported that computer hackers try to break into around 600,000 Facebook accounts using stolen username and password details every day. Facebook has around 800 million users and receives over a billion login attempts every day.
If a hacker takes over a someone's Facebook account, they can do things such as post images, send messages and access all of that person's private information. Facebook is able to determine the number of stolen or compromised logins because it challenges the hackers with additional authentication questions. But this doesn't work 100% of the time and some of hacking attempts are successful. Other common scams include criminals hijacking friends accounts and trying to talk users into sending them money.
One of the new security features Facebook has come up with is called Trusted friends which will allow you to choose 3 to 5 trusted friends who can help you if you have a problem accessing your account if your email or password gets changed. The idea is that if you need to login to Facebook but can't access your email account, Facebook will send codes to your friends that they can pass on to you.