Is it needed to ask the question, "Do you mind being on the internet?", when performing and filiming the spectator? If needed, any suggestions of what I should say?
Just to be on the safe side, I would definitely say "I'm recording this, going to put it on the internet, blah blah blah" so that they know they're being recorded, and if they don't want to be filmed, then they can say No.
My best friend does the weekend magic show at a major amusement park here in Ohio. A street magic pre-show video is shown as the audience is being seated. I was the camera man for that video for the past several years and we always had the spectators sign a waiver stating that they knew they were being filmed and that the film would be shown pubicly. In today's litigation happy society is is always best to cover your ass.