If your facebook account this situation you do not have to worry because you’re not on facebook account hack or your account disabled by facebook.
This has happened probably because you always log in facebook using a different computer or laptop with other words, using a different IP address.
So, facebook took precautions, possible your account accessible by others.
This has also happened to my facebook account yesterday.
Panicked at first because I thought my account had been deleted by facebook.
What should you do?

You just have to follow the instructions provided to ensure that account is true yours.
Between the case that you need to do is know your facebook friends facial.
You may be experiencing problems if you do not know your facebook friends, because I am sure there are those among you only add friends who are not REALLY your friend.
Can not imagine if they deleted my facebook. I will lose the fan page with thousands of followers in other words I lost my money.

can not log in to fb…when prompted to submit required words for security nothing appears…what can I do….