There are many > 1TB tape back up systems, many with very high speeds, assuming you can feed it data fast enough.
I have to wonder though.. 20TB for a single person? I'm not gonna do the math but that sounds like so much stuff to be impossible to listen/watch all of it.
But at least he has proven once again, RAID is not a backup. RAID will merrily do what ever you wish, including copying drive corruption.