Siacoin and Filecoin are basically this; you can store small parts of files under contracts that give you crypto in return. Occasionally you'll get tested by the network to check if it's online, and you have the files you should have. A good use of crypto, though last time I looked the ROI wasn't great as a host.
That sounds more taxing on my connection than what I was thinking. Not really up for 100 connections, but if I'm matched up with 1 or 2 other users then that would seem ok.
From what I understand it doesn't really work like that - files get split in to 30 chunks on different providers, and you only need 10 to restore. Apparently "this means that if 20 out of 30 hosts go offline, a Sia user is still able to download her files."
