I was not free to go about my business, move, or even to exit my vehicle. Because of the intentional actions of other people, who freely admitted to local press that they "wanted people to feel the fear".
Well, RCW 9A.40.040 says such actions are a Class C felony.
RCW 9A.16.020 and RCW 9A.16.050 state that force can be used to prevent such things, or to escape from them.
Furthermore, the way the protestors were milling around in the blind spots of vehicles seemed quite likely to produce injuries. I almost simply parked the car in the middle of the intersection and exited, abandoning the vehicle, save that I was unable to even get out of it.