http://www.youtube.com/watch?v=anCC_LLzWe4

1:55 - A guy in black cloting throws an object at the Seatle Minutemen.
2:32 - Two men in black throw six objects while they stand behind a barrier.
3:10 - Law enforcement steps in and clears the street.
5:10 - Object throwing anarchists cry foul.
5:44 - Speaker says that the police over reacted.
8:12 - Another speaker says that they are for "Open Borders".