I just saw a guy a couple weeks ago getting some heat becasuse his spends all of his free time doing this. He has his own Youtube channel and he post. cops misbehaving. He was "interveing" alittle and provocking(?)them though, so they threw the "obstucting justice" thing at him.
Rodney King's video was from an observer, no one brought up the legalities of it being used in a court of law.
I saw "stay out of the way, why not?". But i dont' know the law so everything i've said is meaningless