The network had already announced that the Games will be live-streamed on NBCOlympics.com and that extra content will be available on Facebook
From NBC:
Q: How do I watch Live Extra videos?
A: When attempting to access a live stream or full replay, you will be prompted to select your cable, satellite or telco TV provider (e.g. Comcast, Time Warner, DirecTV, AT&T) from a list. You then will be asked to verify your TV subscription — this often means only entering the username/password corresponding to the online account you established with your provider.
Back to the OP, I don’t subscribe to MSNBC or CNBC.