https://github.com/ConceptPending/fincrypt
Backups are verified at regular intervals to reduce the amount of trust needed in the system, and every file is stored multiple times.
Eventually the goal is to attach a marketplace where end users will pay for the space they use and those who provide storage will get paid for doing so.
How do you solve the problem of an evil storage node provider who detects that you're trying to recover a file from backup, blocks it and sends you a "transfer X BTC to my account to get your data back" email?
The storage nodes also have no knowledge of who owns the file or what the contents are. Combined with the fact that they'd immediately stop getting paid for the other files they're hosting, it seems like the ROI for one of those evil nodes is pretty negative.