From about:WebRTC in Firefox,
> iceServers:
> urls: ["stun:stun.l.test.com:19000"]
With such a STUN server URL, no wonder nobody ever gets a match…
And it's kind of a nasty bug: it doesn't appear anywhere in the JS console, or in the network tab of the browser, and it's likely to work when testing locally (I haven't tested, but you should not need stun to generate local ICE candidate) so the dev could have tested in local, seen it was working and posted it on HN. Just to discover it was not working after reaching the front page… Sad day for the poor dev.