How It Happens?
Due to increase of especially spammy activities, where they don't need to take over your account to send them, Facebook provides you a way to verify and secure your account by being through a simple wizard. And it will prevent you further from controlling your account or engaging in spammy activities unwittingly. So you don't have to delete your account or try find a way to contact Facebook personnel. If you think someone using your account or experiencing spammy links sending out to your friends and suspicious activities happening on your profile, secure your account immediately. Or help your friends to secure their account if their accounts already engaged in spammy activities.
1. Log in to your Facebook account.
2. Navigate to Secure Account page.
3. Now click Continue button.
* Enhance the security of your Facebook account by enabling the log in notifications. Read Notify When Someone Else Access Your Facebook Account.