I saw this at a music venue. It was strapped onto railings above the audience facing the stage. Says "kick out", is attached by zip ties, looks like a tube wrapped in a durable plastic coat, and looked like it might have a wire running to it.
It appears to be some kind of a rolled up banner, and it probably has a mechanism to remotely release it so it'll unroll.
Hopefully in the process it'll turn out to be short enough not to hit anyone on the head in the process.