That's interesting empirical evidence you have of how suggestible we can be. Hypnotism has always fascinated me, but have never taken the time to deeply look into it. I may be wrong, but I haven't heard about someone having a response of significant influence from a hypnosis video before. I do know however, that hypnosis puts you into a theta wave state, in which you are subject to much more influence then when you are when in an alpha wave state (which TV induces). However, with the excessive exposure that many people have to TV today, with addition to the other tricks used in conjunction with the alpha state, It's effect over time can be quite substantial. As for kids below the age of 7, they are particularly vulnerable to TV programming as during this time they are in a theta state. They are basically in a state of hypnosis during this time while being exposed to TV brainwashing via (media/tv shows/movies). I personally think it would be more disturbing seeing hypnosis done in person, as just like you I saw a performance at my university in which I saw it done to my fellow students. I feel that at least for that time in my life, I would have been skeptical as to the validity of what I had seen if I had merely just seen it on TV, in which can be easily be fabricated.