Apple Blocks Specific Ad Companies on iPhone Browsers... So Who Escaped the List?

The "iOS 27" operating system, launched by Apple in mid-September, has begun cutting off the "Safari" browser's communication with specific named companies involved in user tracking and ad targeting, halting their data collection and ad delivery as soon as the system is installed. "Digiday" reported that it tested over seventy ad domains, and only a small initial list appeared blocked, including "The Trade Desk", "LiveRamp", "ID5", "Permutive", and "Audigent", a subsidiary of "Experian".

The test showed that three companies were not blocked: "LiveIntent" owned by "Zeta", "Lotame" owned by "Publicis", and "ConnectID" belonging to "Yahoo". According to Digiday, the list is located in a private repository on Apple's GitHub platform, giving the company the ability to add new names via a software update to the "WebKit" engine without waiting for a full OS release, an update that has not yet reached users. Since Apple mandates all iPhone and iPad browsers to run on the WebKit engine, the block is not limited to Safari but extends to Chrome, Firefox, and other browsers as well.

Digiday pointed out that The Trade Desk's ad server was removed from the block list in a beta version of iOS, which could mean that users on the current version will not see the fix until the end of this month at the best estimate. Email matching still works outside Safari, allowing some companies to continue this practice. This comes at a time when Apple manages its own ad network, which could have exposed it to accusations of exploiting its dominant position had the block remained as it was. Apple did not respond to Digiday's request for comment.

Rowena Lam, Senior Director of Privacy and Data at the IAB Tech Lab, said that "what this will allow Apple to do is make the block list dynamic," meaning flexibly expandable. Jay Friedman from "Cartograph" believes that "this was not a mistake," because "mistakes happen randomly," adding that "all this does is start a massive game of cat and mouse." Publishers rely on these identifiers to clarify their audience's identity to advertisers, and iPhone readers are among the most valuable readers on the web.

What do these terms mean?

Block list: An internal record maintained by the system developer containing domain names with which the browser is prevented from communicating, thereby halting data collection and ad serving.

WebKit Engine: The software engine relied upon by Apple to power web pages across all browsers on its devices, which is why any restrictions it imposes extend to Chrome and Firefox as well, not just Safari.

Ad Identifiers: Codes used by advertising companies to identify the same user across different websites and display relevant ads to them, a role that has diminished as privacy regulations tighten.