[comntr]

That's right. My first attempt was to use IPFS or DAT. Figured out it's not quite possible, but we can get very close to that, in theory. Imagine the extension or the iframe could run a ipfs.js or dat.js that would discover all the http servers with comments via DHT: servers that want to participate, publish a unique key to the DHT and the web clients discover this key and then the IP addresses of the servers. In practice, this doesn't quite work because DHTs are based on the assumption that any node can quickly ping (with a UDP packet) any other node and thus perform the DHT discovery using the Kademlia algorithm in log(N) steps. But in the web, the only way to "ping" someone is to set up a p2p connection with WebRTC: this not only needs a signaling relay, but also implies a multi step exchange with SDPs and has other costly overhead. And I haven't even approached the Symmetric NAT problem. This is why ipfs.js hogs CPU, allocates a 1 GB and keeps 4-8 sockets always open (they aren't even p2p now, but rather web sockets to some relay, for perf reasons).