WebRTC - scalable live stream broadcasting / multicasting

Question

PROBLEM:

WebRTC gives us peer-to-peer video/audio connections. It is perfect for p2p calls, hangouts. But what about broadcasting (one-to-many, for

Answer 1

"Scalable" broadcasting is not possible on the Internet, because the IP UDP multicasting is not allowed there. But in theory it's possible on a LAN.
The problem with Websockets is that you don't have access to RAW UDP by design and it won't be allowed.
The problem with WebRTC is that it's data channels use a form of SRTP, where each session has own encryption key. So unless somebody "invents" or an API allows a way to share one session key between all clients, the multicast is useless.