#interdependent account recovery - facebook style
food for thought for an alternate to individual back up schemes...
https://www.facebook.com/help/119897751441086?helpref=faq_content
You can choose friends to be trusted contacts in case you're ever locked out of your Facebook account. After you've chosen your friends, they'll be able to send you a recovery code with a special URL you can use to get back into your account.
To choose your trusted contacts:
Go to your Security and Login Settings
Scroll down to Choose 3 to 5 friends to contact if you get locked out and click Edit
Click Choose friends and follow the on-screen instructions
After you've chosen your trusted contacts, you can always click Edit to change or remove the friends you've chosen.
Learn how to contact your friends when you need help getting back into your account.