Friday marked the second anniversary of the eviction at the Occupy Oakland encampment, where tents were were torn down at Frank Ogawa Plaza in front of City Hall after several violent confrontations with police.

To mark the day, about 100 protesters rallied around the Marriott Hotel in downtown, where law enforcement agencies across the country were meeting as part of "Urban Shield" training exercises. First responders and police will learn how to react in the wake of a terrorist attack or a natural disaster.

And vendors are expected to market weapons to law enforcement, which is one of the reasons demonstrators are upset.

Protesters say they targeted this spot because they feel police are becoming too "military-like." They point to Scott Olsen as a flashpoint for the worst that can happen during a civil rights protest. The Iraq War veteran's skull was fractured during a 2011 Occupy protest with Oakland police when a beanbag was fired into his head.

"They're now looking like special operations forces," protester Rick Flickek told NBC Bay Area on Friday.

But Alameda County Sheriff's Sgt. J.D. Nelson said that he feels the anti-police critics represent a minority.

"I think most people prefer to have a well-trained police, fire and EMS system," he said. "Wwhen bad does happen, we are there to help them."

Aside from Olsen, protesters remember two years ago, the violent clashes with police in the streets. Businesses were vandalized, spray-painted, windows broken. Vandals set fires in the street.

Protesters on Friday peacefully gathered at Frank Ogawa plaza, where the movement against financial inequality began.

Oakland Police Sgt. Arturo Bautista said he welcomes any "freedom of speech" activities, as long as they occur "peacefully."

"They have a right to do that," he said. "But we are prepared, just in case they break the law that we'll take some action."

Police said there were no incident Friday night during the protest.