Black Friday shopping along Market Street turned out to be a nightmare as Occupy San Francisco demonstrators picketed in front of stores like Old Navy and Macy's, while also attempting to encamp in Union Square.

On Friday evening, dozens of Occupy SF demonstrators picketed in front of Old Navy and Macy's and protested against consumerism and spending, shouting slogans such as "Today is Black Friday! Don't buy anything today."

Some demonstrators also turned aggressive, forcing the Old Navy store near Powell station to close its shutters, trapping holiday shoppers inside.

The demonstrators also attempted to disrupt the annual Macy's Christmas tree lighting at Union Square, but were prevented from doing so by the police.

The demonstration ended around 9 p.m. PST.

The Occupy SF is a movement against economic and social inequality.

Black Friday Shopping Marred by Occupy SF Demonstrators

Black Friday Shopping Marred by Occupy SF Demonstrators

Black Friday Shopping Marred by Occupy SF Demonstrators

Black Friday Shopping Marred by Occupy SF Demonstrators

Black Friday Shopping Marred by Occupy SF Demonstrators

Black Friday Shopping Marred by Occupy SF Demonstrators

Black Friday Shopping Marred by Occupy SF Demonstrators

Black Friday Shopping Marred by Occupy SF Demonstrators

Black Friday Shopping Marred by Occupy SF Demonstrators