> Since these streams are purely unidirectional, users don't have a way to notice that they're not literally live.
This can be a problem, for example when sports fans receive out-of-band notification of a goal before they see it happen on their "live" stream.
No need for notifications even, you can literally hear latency varying up to 30 seconds by listening for cheers during important game in a block of flats on a warm summer night.
> cheers during important game in a block of flats
Yes, that is what rlpb wrote: soundwaves are richly descriptive out-of-band notifications!
It also makes it impossible to watch a live updating box score without spoilering yourself since it updates before the stream.