... Which assumes people keep their machines running 24/7 on unlimited data connections. It's a nice idea from a tech point of view, but for the life of me I cannot see how it's superior to what we already have.
As far as data volume, I've got to imagine the data usage per user would be significantly less than BitTorrent.
The desirable aspect of this system is obvious - the only people who see your data are people who've seen a QR code from someone in your social graph - your FaceTorrent profile will never, ever be indexed by Google.
What if Google started offering, say, free Google Coupons (assuming they roll their own groupon) in exchange for befriending them on FaceTorrent? Not all of my friends and relatives value privacy as much as I do.