Breitbart News urged its readers to boycott Kellogg Co. after the cereal maker stopped advertising on the news site, whose former chairman is a top adviser to President-elect Donald Trump.

Breitbart lashed back at the company following a statement that Kellogg wouldn’t put ads on sites that “aren’t aligned with our values.” Breitbart Chief Executive Officer Larry Solov said the move was “un-American.”

“The only sensible response is to join together and boycott Kellogg’s products in protest,” he said in a Breitbart story.

Breitbart has become a minefield for brands in recent weeks, with critics lining up on both sides of the political aisle. Before Kellogg abandoned the site, activists attacked the cereal brand for advertising on Breitbart, saying its content espouses racist and anti-Semitic views.

A screen shot showing an advertisement for Kellogg’s Frosted Mini Wheats was part of an online campaign to get marketers to sever ties with the news organization.

A contentious and polarizing election has made it harder for brands to avoid alienating a large base of customers, said Allen Adamson, the former North American chairman of branding firm Landor Associates.

“There are dollars to be made on both sides of the divide,” he said. “It forces brands to make uncomfortable choices.”Kris Charles, a spokeswoman for Kellogg, said it removed its ads from Breitbart after customers complained.

“To be clear, our decision had nothing to do with politics,” Charles said on Thursday after the boycott was announced.

AppNexus Inc., a top digital advertising service, barred Breitbart from using its ad-serving tools earlier this month because it felt the publisher violated its hate-speech rules.

AppNexus scrutinized Breitbart’s website after the news organization’s former chairman, Steve Bannon, was named White House chief strategist. The digital ad firm decided the publication had breached a policy against content that incites violence, according to a spokesman for the company.

Other brands, including Allstate and Warby Parker, have pulled back from Breitbart. BMW said on Wednesday that it too wouldn’t be running targeted ads on the site.

Marketers often buy online ads through third-party tech companies, which distribute them widely across the internet. That means the companies don’t always know where their brands will appear.

Breitbart has drawn flak for its controversial articles, such as a piece that warned of “Muslim invaders” and another that dubbed conservative thinker Bill Kristol a “Renegade Jew.” The site had 19.2 million unique monthly U.S. visitors in October, up from 12.9 million a year ago, according to ComScore Inc.

Some brands have been sticking by the news site. In response to a campaign against Breitbart advertisers, Nissan said it “places ads in a variety of sites in order to reach as many consumers as possible.”

“The placement of Nissan advertising is not intended to be a political commentary and there are no plans to change the advertising mix at this time,” the company said this week.

(c) 2016, Bloomberg · Nick Turner, Craig Giammona