I was involved in this today. It was the first real protest I've done, and it was good - pretty empowering. It was also fortunate that I parked on a street right before the huge crowd marched through it, if I was thirty seconds later I was doomed.
But enough about me - have you ever gone to protests? What were they about? My dad was arrested about Vietnam in the 1970s, so I feel that I've got to continue the tradition somewhat.