We’ve seen these types of systems before and I always wonder how well thought out this is - either on the part of the hosts, the company or the client.
A couple of questions I have right off the bat are:
How do we know how secure this solution is?
Even if it were incredibly well secured - what are the laws around this setup?
If someone stores illegal materials on this system who is responsible? (The person who stored it? The company? The unsuspecting host?)
What happens if the hosts lose interest or it fails commercially? Does the data get lost without warning when hosts start uninstalling the software?
The problems with these systems is almost never the technology - it’s finding a way to negotiate the millions of different implications storing information on other people’s behalf brings.