Facebook is so popular that there are millions of people who have accounts. Hackers can look at your profile information and then decide if you are hack worthy. They may find out about your family background or something. They can then feed this information into a search engine and see if they can come up with anything. From there, it is quite easy to discover your own personal information.
Once they decide that you fit in their ideal mould, then they begin their dirty game. They will not leave any stone unturned to hack the account and extract personal information such as your photos and videos. The ultimate aim is to extort money from you in exchange of the private or sensitive information.
The best advice to prevent such scenario is to never reveal your sensitive personal information on Facebook. Not only should you never reveal your personal information, you should never discuss personal matters on Facebook. That includes asking for help or getting an answer to your problems. If you use Facebook to search for the answers to any of your problems, then you have already revealed your information.
There are a lot of people who share a lot of things on Facebook but do not realize that this can be the cause of a lot of harm later. Just think about what happened with Ashley Madison. People were sharing information on how to cheat on their spouses and how to get their own spouses to cheat on them. Imagine what a chaos must have been created when details of such users got leaked.
Secondly you should not use passwords that can be easily guessed. Most people use their names, birthdays, spouse's name or even phone numbers as passwords, which is a disaster in itself. Always keep a strong alphanumeric password which isn't related to you or your family.
You can stop the hacking just by keeping your profile private. Better yet never reveal anything sensitive that might be used against you.