AT&T doesn't want its name showing up next to videos promoting intolerance and hate. As a result, the carrier on Wednesday said it's pulling ads from YouTube and other Google "non-search platforms."

"We are deeply concerned that our ads may have appeared alongside YouTube content promoting terrorism and hate," the company said in an email. "Until Google can ensure this won't happen again, we are removing our ads from Google's non-search platforms."

Rival Verizon told USA Today that it has also pulled its ads.

AT&T's decision comes days after British retail giant Marks & Spencer removed its ads from all of Google's platforms. Johnson & Johnson also said Wednesday it's pulling its ads from the site. The company said in a statement it takes the matter "very seriously."

The companies joined growing cohort shunning YouTube, including the UK government as well as McDonald's, L'Oreal, Audi, the BBC and the Guardian. To counter the growing backlash, Google on Tuesday said it will give companies greater control over where their ads appear and assign more people to enforce its ad policies.

"Recently, we had a number of cases where brands' ads appeared on content that was not aligned with their values. For this, we deeply apologize," Philipp Schindler, Google's chief business officer, wrote in a blog post. "So starting today, we're taking a tougher stance on hateful, offensive and derogatory content."

The problem is that few companies know where their online ads appear. Most online ad placement services use "programmatic advertising," which targets people instead of websites. That's why when you're online shopping for something like shoes, you may see an ad for those shoes across other sites you visit. Most online ads are sold through massive digital advertising platforms like Google's AdWords, TubeMogul and RocketFuel.

The Times in the UK found that hundreds of companies had ads appearing next to videos created by hate groups or their supporters. The paper found, for example, an advertisement for Mercedes E-class next to an ISIS video praising jihad.

First published March 22, 1:34 p.m. PT

Update, March 23 at 12:47 p.m.: Adds that Johnson & Johnson is pulling its ads.