I know a few of the people who were attacked. I don't have copies of all of the cell phone videos but have seen videos that were not made public. In some videos, you can see bikers fighting back against hippies which were as glorious as you would expect it to be with the exception that the bikers showed great restraint and also pulled a few of their more enthusiastic defenders off the attackers once the attackers went down.
The Students for a Democratic Society at UMN called their event "make racists afraid again". They used stun guns, tear gas, a red smoke bomb, and other miscellaneous fireworks. They were hitting and attacking innocent protesters and bystanders inside the Capitol building.