Blogger John Smith, 67, planned on photographing events during the Olympia Anarchist Convergence, but he was blocked from entering the classroom where the workshop was being held on the third-floor of a building.
"They blocked me and said you aren't welcome here," Smith said. "I said it's a public facility, a public event, but they blocked me, then kind of pushed me out the door."
Smith said he was stepping out to contact campus police when one workshop participant grabbed his digital camera and video camera gear and threw it off the third-story balcony.
The equipment is estimated to be worth $10,000, Smith said.
Campus police attempted to get the names of the people involved, but the student group would not cooperate, The Olympian reported.
Police were intending to cancel the event when they discovered those involved had already left. Officials said they will not allow it to reconvene on campus.