The truth is, a lot of people stream. I know for a fact I have been on lots of people's streams - in random dungeons without my knowledge, in hunt parties, in the background, even had a streamer invade a savage party and clear it with their viewers, sometimes they've indicated it with "twitch" in their character name and sometimes I've discovered it by looking at their Search Info. I've also joined PFs to help streamers clear before, because their viewers weren't actually sufficient alone.

But the vast majority of these streamers are small - perhaps with 0-2 viewers anyway, or just a small number. I'd imagine the larger streamers might make a person more uncomfortable, or if they are uploading to youtube.

Personally, I just accepted I'm probably being streamed a lot without my knowledge. I encourage streamers to block their chatbox to protect private conversations, but there are some naive streamers that don't. But it is something I alert them about if I watch small streamers.

As far as the icon goes, we already have a camera icon in use, so it would need to be a different icon.