Re: "Don't worry Folks, everything is fine"
"We had life before cars and electricity, too."
We had life before horse and cart. We had life before steam locomotion. We had life before gas lighting. All those things were indispensable in their time but we discovered alternatives. The end of history is a fallacy; every age has thought it had achieved the pinnacle of human achievement.
"And no, various family values preclude ignoring people for whom Facebook is the exclusive contact point."
How about telephones or are you post-telephone? How about letters or are you post-letters? Email? MySpace? If you can dispose of those to communicate only by FB, something you (plural) must have let happen by mutual consent because nobody actually forced it on you, then you can also dispose of FB.
You may not have any contingency plans in place but you'll struggle on somehow.
Don't think FB is too big to fail. There's no such thing. Banks weren't allowed to fail because they were too big, they were allowed to fail because they were too embedded in the workings of the economy. That took a few centuries to happen, not a few years.