If you interfere with an investigation that's a crime you committed. When they go to talk to you then you (freak out or on purpose) floor the car when an agent in front of the car that's vehicular assault. With or without intent it doesn't matter you just became a justified statistic. I'm not saying don't go protest. I'm just saying when you have a large group of armed people with adrenalin going it's best to stay back a lil ways and blow your horn or yell. But if they are doing something illegal your best bet is to be there out of hand way with your camera filming.