Completely theoretical question: What if a file system existed such that each user in a block chain dedicated some bandwidth and and storage on their machine to be part of an extremely scaled up version of RAID over a distributed network? Copies of small sectors would be stored in multiple places, and places would be favoured by proximity (for better latency). If someone moved location, the remote sectors from the moved user could bubble into a more appropriate location. Could this work? What would be the drawbacks?