*FB servers went down. It sounds like a hack until you learn that their actual DNS name servers were deleted from the registrar. Nothing to see here, they could have updated their DNS, right?
Until you learn that the FB employees couldn't get into the building (their key cards didn't work) to figure out what caused the site to go down and to get the servers back online again.
Hours later everything just comes back on but moving slow? I have a guess. The military raided FB for the servers, took them, and left. When FB regained access to the facility they had to switch to the backup servers, which took a few hours to rebuild.
Now we're seeing FB back online...but who's really in control over it now? Something a LOT BIGGER just happened today, people.