ST. LOUIS, the United States, Nov. 28 -- Nationwide protests against a grand jury decision to acquit a white policeman who shot dead an unarmed black teenager disrupted the usually busy shopping activities of Black Friday, as demonstrators turned to capitalize on commerce.

After a mostly quiet Thanksgiving Day, protesters went out on Friday to boycott the biggest shopping holiday of the year in the United States, aiming to highlight the limited purchasing power of black Americans and draw links between economic inequality and racial inequality.

Two large shopping malls in Missouri were shut down, where white policeman Darren Wilson shot and killed 18-year-old Michael Brown on Aug. 9 in its suburb of Ferguson.

At least 200 protesters entered the Galleria Mall just south of Ferguson shortly after 1 p.m. local time on Friday, lying on the floor to block footsteps, chanting "Stop shopping and join the movement," and "No Black Friday."

The atmosphere was more festive than tense, but stores were still closed. The mall's jewelry store was closed as soon as protesters entered the building, and several other stores also lowered their security doors or locked entrances.

Eddie Cox, a black assistant manager of a Lids baseball cap store, said he watched the peaceful demonstration with pride.

He said his store was seeing a four-fifths drop of Black Friday sales on a year-on-year basis owing to the activists' call for boycott.

Black Friday, the day after Thanksgiving, traditionally kicks off the holiday shopping season in the United States with retailers offering big discounts.

"The business side of me kinda hates it, but at the same time, the young, activist, pro-conscious part of me loves every bit of this," he said. "It's a really cool time to be young, black and American."

The demonstration stirred up worries and chaos. Debbie Montgomery, an anxious shopper, told Xinhua: "I'm here doing my holiday shopping with my 82-year-old mom. I can't find her now. How long will this go on? Are they leaving?"

Another shopper Abe was uneasy about speaking out in front of protesters. "I think it is time to hold your words and let people do what they're gonna do." He said and then quickly took his wife and daughter away from the protesters.

Later, the protesters left, regrouped at a park and drove to West County Mall to force it shut.

The grand jury decision announced on Monday means that Wilson will not face state charges for shooting Brown dead, triggering public outrage over racial discrimination and debates about racial relations in the United States.

The shooting of Brown was not an isolated event in American policing. Long periods of segregation, racism and marginalization of the minorities have become the bane of community division and social riots.

In New York, more than 200 people on Friday sought to disrupt shopping with a protest in front of the Macy's store in Herald Square and marched into the ground floor under the surprised gaze of staff and shoppers.

"We want them to think twice before spending that dollar today," Kristiana Colon said at Chicago's popular Magnificent Mile shopping district, where about 200 people gathered for "a day of awareness and engagement" as they called.

"As long as black lives are put second to materialism, there will be no peace," she added.

Similar protests were also staged in other cities including Los Angeles and Oakland of the state of California. Protesters blocked off a train station in the San Francisco Bay area.