The venues for these things are private and so they can set their own rules. The author proposes a rule: A simple purple lanyard indicating that you don't wish to be included in the published film.
This doesn't necessarily need to be an article, because the author could have just handled it with each venue individually, but this just gets the conversation going about general sentiment and wider applicability.
My guess is that early on this kind of youtuber was relatively rare and so being captured occasionally wasn't a big deal, but that now the trend is catching on, a it's happening regularly and becoming a concern for some people.
This doesn't necessarily need to be an article, because the author could have just handled it with each venue individually, but this just gets the conversation going about general sentiment and wider applicability.
My guess is that early on this kind of youtuber was relatively rare and so being captured occasionally wasn't a big deal, but that now the trend is catching on, a it's happening regularly and becoming a concern for some people.