Suppose Facebook suddenly encounters a bug that allows people to log into any account without a password. Users are unable to change their settings. All posts can be viewed by everyone. After about half an hour and a lot of on-line protest, when Facebook tries to address the issue, they find that they are unable to modify their own code, neither are they able to stop it. Most of the code initially written for FB has been deleted.
They realise that all their servers across all offices have been infected and are being controlled remotely. They take all their servers off-line by manually disconnecting them. On further investigation, they also find that every computer that they're using has an embedded code in its operating system that permits this. Most people suspect that this has been planned for, and that insiders must have played a major role in it.
6 hours have passed, and now various organisations have been contacted. There has been no information from the hackers themselves. Facebook has copied all the data from the computers into secure hard drives.
12 hours have passed, and no major leads have been found. People are seriously beginning to question whether the events that just happened were even logically possible and there are small groups with the company itself who are starting to believe in paranormal explanations.
Days pass, and no information has been found. Facebook has suffered heavy economical losses.
What will happen now?
Will they try restarting from scratch, buying new hardware and rewriting all the code required?
Or will they create an interim website that allows people to download their data, following which they will shut down?