Another wave of prominent advertisers, including both major U.K. political parties campaigning for Thursday's election, suspended commercials on YouTube after their ads appeared before videos promoting extremist ideology.
The moves follow a deadly terror attack in London that killed eight, the third lethal attack in the U.K. in three months. Prime Minister Theresa May has castigated Silicon Valley for not doing enough to police content on social media and the internet. Marketers have for months complained about their ads popping up next to offensive content, in many cases pulling ads.
Britain's ruling Conservative Party, the main opposition Labour Party, Etihad Airways, owned by the emirate of Abu Dhabi, and privately held meal-delivery business Deliveroo all said they would stop advertising on YouTube, a unit of Alphabet Inc.'s Google, saying the video site needed to better control where commercials appear.
"We have made it clear to Google, it is completely unacceptable for our ads to be running on these videos," a Conservative spokesman said, adding the party won't resume advertising on YouTube "until we receive suitable assurances that this will not happen again." Labour, Etihad and Deliveroo issued similar statements.
The Times of London reported finding the ads playing before videos promoting Islamic extremists, and the newspaper said it had informed the advertisers.
A YouTube spokeswoman said Wednesday that the site had been reviewing its advertising policies and was working to further improve control of where ads appear, in addition to recently announced changes. "We never want terrorists to have a voice, or spread extremist material on our services," she said.
The latest volley from advertisers underscores how YouTube has struggled to control where ads appear. Google in April released new measures to help marketers track where ads pop up. That came after a backlash from major advertisers, including the U.K. government. They complained that their commercials were appearing before objectionable videos.
One of its new features allows third-party companies to monitor where ads appear on YouTube and to report back to marketers on the "brand safety" of the videos. Advertisers have said Google also planned by the third quarter of this year to give them a tool that provides a full list of videos against which their ads appear and how many times their ads were displayed on each.
One major British advertiser, London-based Vodafone Group PLC, has gone beyond just complaining to Google. The world's second-largest mobile carrier by subscribers this week announced new guidelines that govern where Vodafone advertisements appear. Vodafone said employees at its advertising agency will track where the ads go.
Vodafone spokesman Matt Peacock, who helped draft the guidelines, said that ad placement on YouTube is typically determined by a so-called blacklist approach. YouTube scans videos and their written description to determine whether they are related to pornography, gambling or other objectionable content. Then it can block a brand's ads from appearing before such videos.
The problem is that it is hard for a computer to determine whether a video promotes extremist content or false news reports. "You need a human being to do the analysis," Mr. Peacock said. Vodafone is adopting a "white list" approach, he said. Using a mix of computer intelligence and humans, it is drawing up a shorter list of video creators that are "brand safe," and directs YouTube to post its ads only with that content.
YouTube owner Alphabet reported a sharp increase in first-quarter revenue, continuing rapid growth that seemed unscathed by boycotts from some of its major advertisers. Many of the advertisers pulled their commercials after the first quarter concluded, however, so second-quarter results may shed more light on any impact.
--Robert Wall contributed to this article.
Write to Stu Woo at Stu.Woo@wsj.com
(END) Dow Jones Newswires
June 07, 2017 13:31 ET (17:31 GMT)