I had the opportunity to sit in on a meeting with an industry expert who was discussing storage solutions for large-scale, object data. Photo archives like Shutterfly were actually mentioned as user examples. The file system being used in these cases is based on Tahoe-LAFS, an open-source software application.
The system has a number of advantages including fault tolerance, operation across multiple storage locations and encryption. It can run on your own machine or it can run on your machine with 'replication' across multiple other users connected through the internet. It is ideal for infrequently accessed data (like old photographs) but not suited to data base applications (you wouldn't want your Lr catalog on this).
I believe I have heard of shared storage systems for personal use, though I don't recall much about them. I suspect they use this technology. Is anyone in this forum familiar with the technology? I sounds like a practicle method of data backup, if a few dozen users could come together to form a storage pool.
More information is available at https://tahoe-lafs.org/trac/tahoe-lafs/browser/docs/about.rst#