I understand her getting cuffed after retaliating, but there was no reason for cops to be jacking her in the back of the head with nightsticks. If she refuses to move, peacefully arrest her. The police need to show restraint. Getting heckled by some college kids is NOT good enough reason to start bashing people in the back of the head as they are trying to walk away from you.
Peaceful protests do no warrant unprovoked violence from the police. If they want to peacefully disobey police orders as an act of civil disobedience, they should be able to do so without getting bashed in the head with a nightstick.