What you're looking for is Oblivious Transfer or Mix Nets. Unfortunately, no practical solutions currently exist (except for Onion Routing).
> Remember that data can be encrypted by content hash, so there is no way to know what you're storing unless you go scouring the public internet for a key to decrypt it.
Censorship does not work this way. First, content that requires censorship resistance is usually public, otherwise one can employ a number of p2p or centralized solutions to share content directly.
Public content is easy to find, so step one: you find and identify the list of nodes that serve the content. Step two: you block the nodes on a level that's available to you (depends on the country). Step three: your users are unable to use the network effectively, because half of the nodes don't work, and revert to using Facebook.