Facebook now blocks users’ ad blocker software

SAN FRANCISCO — Digital ads pop up online so frequently and ubiquitously that many people are using software to block them.

But if you try to stop ads from showing up on Facebook’s desktop website, you will now be out of luck: The social network has found a way to block the ad blockers.

On Tuesday, Facebook flipped a switch on its desktop website that essentially renders all ad blockers — the programs that prevent websites from displaying ads on the page when a user visits the site — useless. The change allows the Silicon Valley company to serve ads on its desktop site even to people who have ad-blocking software installed and running.

“Disruptive ads are an industry problem, and the rise of ad blockers is a strong signal that people just don’t want to see them,” Andrew Bosworth, vice president for Facebook’s ads and business platform, said in an interview. “But ad blockers are a really bad solution to that.”

Facebook’s move is set to add to a furious debate about the ethics of ad blocking. On one hand, many digital ads are a nuisance — they slow loading times of web pages and detract from the online experience. Yet the ads also serve as the business foundation for many digital publishers to provide content to readers.

Ad blockers have become a threat to publishers including The New York Times and The Wall Street Journal, which are facing declining advertising revenue. About 200 million people worldwide use ad-blocking software on their desktop computers, according to estimates from PageFair, an anti-adblocking startup. An additional 420 million use ad blockers on their smartphones, the company said.

Several digital publishers, including Wired, Forbes and The Times, have begun experimenting with anti-ad-blocking techniques, including asking visitors who use ad blockers to “whitelist” their sites so that ads may still appear.

“We need to spell this out clearly to our users. The journalism they enjoy costs real money and needs to be paid for,” Mark Thompson, president and chief executive of The Times, said at an ad industry conference in June where he addressed ad blocking. “Advertising is a vital part of the revenue mix.”

Bosworth of Facebook said ad blockers were “certainly bad for the publications who are robbed of half of the value exchange between users and publishers.” But rather than blocking all ads, he said, Facebook needed to find a way to serve better ads.

Facebook’s move is perhaps the strongest anti-adblocking measure taken by a major technology company, especially one that serves advertising to more than 1.7 billion monthly users globally. The effort is risky for the company, which prides itself on delivering the best user experience, because it could alienate some people for whom ad blocking is an ideological stance on how they wish to gain access to the internet.

To shut down the blockers, Facebook is taking aim at the signifiers in digital ads that blockers use to detect whether something is an ad. Facebook’s changes will then make ad content indistinguishable from nonadvertising content.