I seem to remember as a young child being told that it is safe to touch a Van de Graff generator (for the hair demonstration), but that if you let go before it is safe you will get a nasty shock. I know a bit more about electricity now, and I’m a little skeptical now. Is it possible to get a shock from letting go of something?
I see. Would there also be an arc if you put your hand near the generator while it was running, then?
As long as the potential is great enough to break down the dielectric of air yes.