Free communication on the internet presently relies almost entirely upon the good will of various service providers to give people discussion spaces. I'm sure we are all familiar with how frequently this good will ends due to commercial or political interests. Moderation can also be a risk. Humans are fallible.

We need a public discussion space which is immune to these failings,

Hence a system whereby posts are anonymous and are stored across every node in the network such that there is no single weak-point a censor can target is needed. A bittorrent but for discussions. People who've been involved with tech for a long time might recognize that Usenet had similar functionality too.

Usenet is unfortunately somewhat deficient because it's present heavy filesharing use discourages acting as a server and it relies on infrastructure which requires a seperate service provider from the ISP in most cases.

Usenet servers typically delete content based purely on age. An improvement would be to inspect which peers you are connected to have which content and delete the most widespread content first. Hence, content can take longer to disappear from the network with the same storage capacity as one based on just time along.

The other modification from bittorrent would be to drop the tracker system and focus on DHT (trackers are a weak point).