Aside from the fact that the largest size of a DB os 500TB, assuming you even had something that large.

How Many:

Teamed Network Cards?

HBA Controllers?

Drives (Max MDF file is on 16TB)

What server could handle 25 1GB network cards and 50 controller's?

How much total SAN space does the enterprise have? Few places have 1 PB of SAN Space just for data, let alone backups.

It could not be backed up over copper, fibre would still be very time consuming, even with the best router?

You could never DR it, the amount of time to logship/mirror multiple T3's would be very long...plus you would need that much space at the DR side.

I'm sure it's 800GB, but it's interesting to think of it it could be 800TB. However, I think given a max DB size of 500TB, he has to mean 800GB