Ask HN: Is there a home Dropbox-style solution? (better explanation inside)

Context: My home was broken into while I was out of the country. Thankfully, they did not find my backup hard drive with irreplaceable files on it. I began thinking of my family members (less technologically inclined), and realized that they would never pay for a backup service (because they don't see the need for it yet), but I know that they need it. I also know the amount of info that they have in multimedia (pics and home video) alone is huge, which would make it prohibitively expensive to use most commercial solutions.

It would be interesting to have a home-based backup with RAID-like capability (specifically, parity checks), that could be shared between home (commodity) computers in different locations over the Internet. For example, 3 family members could serve as backup locations for one another and, potentially, cloud access for personal files. Encryption could be included so as to protect private contents. Alternatively, files could be openly shared (family pictures and music!). Parity could ensure redundancy in the event of loss of one of the computers, and the backup could be reconstituted from the remaining nodes.

Does anyone have any further insight on this?

If there's not an existing solution, does anybody want to work on one? There's business possibilities in it, for sure!