Shares of Nike fell 3.2 percent on Tuesday as calls for a boycott of the sportswear giant gained traction on social media following its choice of Colin Kaepernick as a face for the 30th anniversary of its “Just Do It” slogan.

Former San Francisco quarterback Kaepernick, the first NFL player to kneel during the national anthem as a protest against racism, posted a black-and-white close-up of himself on social media on Monday featuring the Nike logo and “Just do it” along with the quote, “Believe in something. Even if it means sacrificing everything.”

Over 30,000 people were tweeting with the hashtag #NikeBoycott on Tuesday morning, making it among the top trending topics on Twitter. Some posted images of themselves burning and ripping their Nike shoes and apparel.

“First the @NFL forces me to choose between my favorite sport and my country. I chose country,” Twitter user @sclancy79 said in a post retweeted 16,000 times. “Then @Nike forces me to choose between my favorite shoes and my country. Since when did the American Flag and the National Anthem become offensive?”

Nike shares slipped to $79.60 amid the controversy, but are still up more than 25 percent this year.

Still, there were a large number of other users who reacted positively to Nike taking a stand on social issues.

Athletes including LeBron James and Kevin Durant showed support, posting images of Kaepernick’s ad on their Instagram profiles.

Retail industry analysts were divided on whether the heat around the campaign would be a commercial positive for Nike or ultimately alienate and lose customers.

“The alt-right calls for a Nike boycott will fail just like the boycott of Dick’s Sporting Goods failed,” said Matt Powell, a senior adviser with market research firm NPD Group. “Old angry white guys are not a core demographic for Nike.”

Gun rights supporters called for a boycott of Dick’s Sporting Goods earlier this year after the retailer stopped selling assault rifles and high-capacity magazines following a massacre at a Florida high school in February.

Another analyst, GlobalData Retail’s Neil Saunders, said the campaign will harm Nike in Middle America, where it is battling Germany’s Adidas for dominance in the sneaker market.

“The company’s stand may go down well on its native West Coast; it will be far less welcome in many other locations,” he said.

President Trump has been critical of athletes taking a knee during the national anthem and has said he would love to see NFL owners fire football players who disrespect the American flag.

Nike, who confirmed on Monday that Kaepernick was part of the campaign and called him “one of the inspirational athletes of his generation,” did not immediately respond to requests for comment on Tuesday.