The Facebook Security team sent the following guidelines to help keep my account secure in future:
1. Password Protection: You should select a unique and complex password for your account and keep this entirely to yourself. Be sure that you use a complex string of numbers, letters, and punctuation marks that is at least six characters in length. It should also be different from other passwords you use elsewhere on the internet.
2. Private Browsing: Please make sure that you log out of your Facebook account and quit your browser when you’re done using the site. This is especially important when using a public computer or someone else’s mobile device. You should also never check the "Remember Me" box when logging in from a public computer, as this will keep you logged in even after you close your browser window.
3. Secure Email: Since anyone who can read your email can probably also access your Facebook account, you should make sure that any email addresses associated with your account are secure. To ensure security, you should change the password for all of your email accounts and make sure that no two are the same. By varying your passwords, you can greatly decrease your account’s risk of being compromised in the future.
4. Security Question: If you have not done so already, you should add a security question to your account from the Account Settings page. You should choose a question and answer that you will remember, and no one else should be able to answer the question that you choose.  Please note that if you do not see the option to add a security question, this means that there is already a question and answer associated with your account.
5. Log in at Facebook.com: Make sure that when you access the site, you always log in from a legitimate Facebook page with the facebook.com domain. Do not click any unfamiliar links and do not run any executable files (files ending in .exe) on your computer without knowing what they are. If something looks or feels suspicious, go directly to www.facebook.com to log in.
6. Run Anti-Virus Software: If your computer has been infected with a virus or with malware, you will need to run anti-virus software to remove these harmful programs and keep your information secure.
7. Learn More: You should visit the following page for more information about Facebook security and how to report suspicious material in the future: http://www.facebook.com/security.