Q: Filters can block both pull & push messages by whitelisting origins. Making encrypted digests doesn’t help with that problem of extreme censorship. What about that?

A: It helps in the sense that there are usually workarounds with lower bandwidth & longer latency. The message format makes it much easier to use them (including sneaker net as a link). Steganography is also easier at lower bandwidth. Usually people at work are able to receive email forwarded from their home address. So if someone says I can watch at home & not at work then I immediately think of such routes.