CHICAGO (CBS)-- Some visitors in Chicago to protest the NATO summit say Chicago police harassed them Wednesday, and they have video they say proves it.

The group was traveling to Occupy Chicago headquarters on Cermak just west of Chinatown when they were pulled over by Chicago police officers.

They videotaped the encounter.

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“Do you guys have something planned for next week?” one officer asks the group, an apparent reference to the protests planned during the NATO summit of world leaders at McCormick Place on May 20-21.

One of the men in the car replies, “No, not really.”

“Nothing on the horizon?” one officer asks.

Another protester asks why the police are pulling people over “for no reason.” The group said it was just turning their car around.

The officer responds that the group was turning around in private property.

“We were just turning around, man,” one of the Occupy members says.

“That’s private property, buddy,” an officer responds.

At that point, another officer started talking about the 1968 Democratic National Convention, where protesters and rioters clashed violently on the street.

“’68, do you know about ’68?”

“Billy clubs to the ——– skull,” one officer says.

At another point, one of the passengers tells the officer that they will “see them at NATO.”

“Can’t wait,” one officer responds. “We’ll come looking for you, each and every one of you.”

The Occupy Chicago group claims that was harassment.