> How many of us sympathise with the idea of running a Tor exit node, for example, but avoid it because we're worried about the consequences?

Tor isn't the best example, because exits don't cache anything. So mainly, exit operators get complaints. And the exit IPs end up on block lists. Operators don't typically get prosecuted. Maybe they get raided, however, so it's prudent to run exit relays on hosted servers.

Freenet is the better example. The basic design has nodes relaying stuff for other nodes. In an extremely obscure and randomized way. Also, keys are needed to access stored material.

However, nodes see IPs of all their peers. Investigators have used modified clients to identify nodes that handle illegal material. So users get busted. There is "plausible deniability". But it's not so plausible when prosecutors have experts that bullshit juries. So users typically plea bargain. Or, if they use encrypted storage, they get pressed for passwords. Like that guy in Philadelphia.