Six trade and marketing organizations this morning published an open letter to Apple asking the company to "rethink" plans to launch new versions of Safari in iOS and macOS that block cross-site tracking, and this afternoon, Apple offered up a response, which was shared by The Loop.

According to Apple, ad tracking companies are essentially able to recreate a person's web browsing history using cross site tracking techniques sans permission, something it's aiming to stop.

"Apple believes that people have a right to privacy - Safari was the first browser to block third party cookies by default and Intelligent Tracking Prevention is a more advanced method for protecting user privacy," Apple said in a statement provided to The Loop. "Ad tracking technology has become so pervasive that it is possible for ad tracking companies to recreate the majority of a person's web browsing history. This information is collected without permission and is used for ad re-targeting, which is how ads follow people around the Internet. The new Intelligent Tracking Prevention feature detects and eliminates cookies and other data used for this cross-site tracking, which means it helps keep a person's browsing private. The feature does not block ads or interfere with legitimate tracking on the sites that people actually click on and visit. Cookies for sites that you interact with function as designed, and ads placed by web publishers will appear normally."

In the open letter, signed by the Data and Marketing Association and the Network Advertising Initiative, among others, the collective "digital advertising community" said it is "deeply concerned" because the update "overrides and replaces existing user-controlled cookie preferences" before going on to suggest that customers prefer targeted ads.

"Apple's unilateral and heavy-handed approach is bad for consumer choice and bad for the ad-supported online content and services consumers love," reads the letter. "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."

In both macOS High Sierra and iOS 11, the Safari web browser is gaining new privacy features to prevent companies from tracking customer web browsing habits across websites. "The success of the web as a platform relies on user trust," Apple says on the WebKit blog. "Many users feel that trust is broken when they are being tracked and privacy-sensitive data about their web activity is acquired for purposes that they never agreed to."

In iOS 11, the toggle to turn off cross-site tracking is available by going to Settings --> Safari --> Prevent Cross-Site Tracking. With macOS High Sierra, the feature can be accessed by going to the Preferences section of the Safari app, choosing Privacy, and then checking "Prevent Cross-Site Tracking."

iOS 11 will be released to the public next Tuesday, September 19, while macOS High Sierra will be released on the following Monday, September 25.