NetNewsWire ad blocking caused linked words to vanish from a Daring Fireball article, according to Daring Fireball writer John Gruber, after the RSS reader’s built-in CSS matched a link to Apple’s advertising site and hid the entire anchor.
Gruber said the problem appeared in his column, “John Ternus Should Reverse Apple’s Slide Down the Advertising Slippery Slope.” In that piece, a sentence said Apple was launching “ads on Apple Maps,” with those words linked to ads.apple.com/maps. Readers using NetNewsWire did not see the linked phrase, leaving the sentence looking as if Gruber had failed to finish it.
After readers reported the missing words, Gruber said he suspected the ads.apple.com domain. Daring Fireball reader Antonio Germano then checked NetNewsWire’s open-source code and found the relevant rule in the app’s core.css file. The CSS section is labeled “Block ads and junk” and includes selectors that hide links whose href contains patterns such as “.ads.”, “feedads”, “doubleclick” and “//ads.”
Why did NetNewsWire hide Daring Fireball text?
The mechanism is blunt: the rule does not only disable navigation to a matched ad-related URL. It applies display: none to the link element, so the visible words inside that link disappear with it. In this case, the URL pattern matched Apple’s ads.apple.com domain, and NetNewsWire removed the linked words from the rendered feed item.
Gruber said he had not known NetNewsWire filtered content in this way and added that he thinks it probably should not. He reported the issue to Brent Simmons, the developer associated with NetNewsWire, after Germano identified the CSS rule.
Gruber also said he considered a workaround: replacing the direct Apple URL with a shortened redirect, such as a Bitly link pointing back to Apple’s page. He decided against it, saying he did not want to use mystery URLs or maintain redirect tricks to compensate for another app’s filtering rule. He also argued that direct links are better for web pages meant to remain useful for years.
The NetNewsWire case is not the only example Gruber cited. He said the Safari extension Banish, which he recommended in 2022, later began hiding linked text that pointed to Apple’s App Store domain. According to Gruber, that meant readers with Banish installed could lose words, including headlines, from posts containing App Store links. He said he reported the issue to Banish’s developer twice without receiving a response and planned to update his earlier recommendation.
Gruber’s complaint is narrower than a general objection to ad blocking. He wrote that content blockers ideally remove only what users intended to block. His objection is to filters that silently erase ordinary article text, because readers may blame the publisher for what looks like an editing mistake.
He also asked Daring Fireball readers who use ad blockers to consider allowing ads on the site. Gruber said Daring Fireball runs one display ad per page, serves ads from daringfireball.net, does not use cookies or JavaScript for ad tracking, and rejects advertiser requests to serve images or tracking pixels from outside domains. He said Magic Lasso does not block Daring Fireball ads by default, while uBlock Origin Lite can be configured to allow them.
Gruber added that readers remain free to block the site’s ads and said Daring Fireball does not run JavaScript to detect ad blocking or nag users about it.
This story draws on original reporting from Daring Fireball.
