So, someone deleted large sections of the routing....that doesn't mean Facebook is just down, from the looks of it....that means Facebook is GONE.
https://twitter.com/BenjaminEnfield/status/1445104389014835213?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1445116825021394944%7Ctwgr%5E%7Ctwcon%5Es3_&ref_url=http%3A%2F%2F8489
Upstream netblock deletion from routers.
An Over simplistic analogy: Think pruning a tree of limbs