Not sure how longs its been there but Kordia seem to be broadcasting a hidden channel in Dunedin at the moment (and I assume elsewhere)
This is currently showing a live stream of the Accelerate World Conference https://twitter.com/WorldAccelerate
We couldn't tune this in on a Sony TV as it seemed to ignore the channel but a chinese DVB-T box picked this up fine.
Freq: 36 (Kordia)
Video ID: 550, Audio ID: 600