Facebook is back online again.
It appears they switched over to their QA/UAT systems. It's up and down all over the place, with people reporting missing data and missing posts. It's not up where I am and still down in large parts of the world. Switching to QA is usually an act of desperation.
This wasn't an accident or a fluke, but was done on purpose. Question is who and why. And whoever did this to production, could much more easily do it to QA.