If you fear your information has been harvested without your consent from Facebook and want to delete your FB account, or at least temporarily disable it (till the system becomes more secure), follow these steps:
Deactivate your account for some time
Doing so will temporarily disable your Facebook account and also at the same time eliminate your name from the things you have shared or tagged. To do so just click on the down arrow button on the top blue bar of Facebook on your desktop/laptop and scroll down to deactivate your account. The system will ask your password to confirm. You can again activate your account by logging on to www.facebook.com and keying in the user name and password.
Deleting the account forever
Had enough of the social media website? Don’t want your personal data to be leaked to anyone else. You can delete the FB account once and for all. Remember doing so will delete everything you ever stored or created on Facebook, including messages, videos and photos. You would need to visit Facebook’s account deletion page here and press delete my account. Some websites do say that it will take between 60-90 days for the servers to fully delete your data. However, once you click delete you will not be able to access it ever again. So tread carefully.