We went to the World Snooker at the weekend. Was good. You could rent these little radios to listen to the whispering-in-the-background bit of the TV commentary, so you can hear what's going on but not disturb the play.
So you get this strange dynamic where some of the people there are connected by a secret audio channel, some people are in on a secret joke and some aren't.
For instance, while one of the players was lining up a shot someone in the crowd sneezed, and one of the commentators, in the ears of about a third of the people, said 'bless you' and a bunch of people did a little giggle. So, if you didn't have earphones, you'd have heard - sneeze, pause, giggle. With slightly strange timing. And every now and then, there'd be a joke on the commentary and a bunch of people would laugh and the players would wonder what was going on.
Not a big thing but an odd dynamic that you could probably work up into a reckon on Medium about social networks. Or maybe it's one for the analogy library.