NEW YORK: Six major advertising industry trade associations have signed an open letter attacking Apple’s “heavy-handed” approach to setting cookies in the latest update of its Safari browser.

The American Association of Advertising Agencies (4A's), the American Advertising Federation (AAF), the Association of National Advertisers (ANA), the Data & Marketing Association (DMA), the Interactive Advertising Bureau (IAB) and the Network Advertising Initiative (NAI) banded together to express their concerns about a particular feature of Apple’s Safari 11 browser.

“We are deeply concerned about the Safari 11 browser update that Apple plans to release, as it overrides and replaces existing user-controlled cookie preferences with Apple’s own set of opaque and arbitrary standards for cookie handling,” they said.

Crucially, they argued, Safari’s new Intelligent Tracking Prevention (ITP) feature will “change the rules” by which cookies are set and recognized by browsers.

This, The Drum explained, is designed to limit the ability of website owners and advertising platforms to track users across domains.

“In practice, this means that the cookies advertisers rely on for measurement will be unavailable after 30 days, and cookies for targeting and retargeting in media will be unavailable after 24 hours,” it said.

The trade associations condemned Apple’s “unilateral and heavy-handed approach” which they said would be bad for consumer choice and bad for ad-supported online content and services.

“Blocking cookies in this manner will drive a wedge between brands and their customers, and it will make advertising more generic and less timely and useful,” they argued, as they urged Apple to rethink its plans.

The ITP initiative was trailed back in June at an Apple developer conference, when Apple executives stressed that ads weren’t blocked just previous browsing data – so ensuring user privacy.

But, as Search Engine Land noted, Safari accounts for almost half of mobile web traffic in North America, meaning that ITP “has the potential to wreak havoc on mobile ad conversion attribution”.

Earlier this month, Google announced a new Google Analytics cookie designed to capture campaign and conversion data from Safari in a way that conforms with ITP.

Data sourced from 4A’s, The Drum, Marketing Land, Search Engine Land; additional content by WARC staff