It's not uncommon for big companies to have terabytes of storage. I used to work for one. Our tape library held 24 terabytes. Our nightly backups (differential backups) were running between 300-500 gigabytes and our weekend backups (full backups) were running 1.2-1.5 terabytes. I don't know who has the largest storage but I'd bet it's Lucasfilm. I don't know if anyone has petabyte storage.