I think the user raises valid concerns that should be discussed.
Freenet (~2000) did something similar. They distributed and cached content across all participating nodes. Users were storing encrypted fragments of other's data. It was notorious for distributing illegal content.
I recall that at the time, users were concerned about illegal content winding up on their computers - even if they weren't directly - knowingly - downloading those resources.
As I looked a little deeper just now, I'm discovering that courts have generally been lenient on unknowing participants - that intent and knowledge do matter. It's still a legal grey area (from some basic research I just did - maybe someone else can add to this).
I would still be concerned about a corrupt agency (in some fascist environment) pressing charges or insinuating illegal activity regardless of intent.