This sign clearly tell that Apple has open the war to unscrupulous advertisers. By the way it is also a good way for the Cupertino firm to force advertisers to use the new technology he has introduced with iOS 6: "Limit Ad Tracking" and also its ad agency "iAd."
Basically, what is a cookie ?
It is a small file stored on a computer to improve navigation on a website, or to remember the user's session. How cookies work on a smartphone like the Apple iPhone is the same as on a computer: a small file that saves information about a user or visitor of the site or an application that can be used later when it returns to the site or application.
Ok and now ?
Before the unveiling of iOS 6, the UDID (unique identifier of an Apple device), an identifier created by Apple had had good use (to bring new features, for example) but often diverted by advertising and unscrupulous developers to perform tracking and display targeted advertisements and / or even get data they are not supposed to have on users.
With iOS 6, Apple has removed access to the UDID and introduced a new feature called "Limit Ad Tracking". Advertisers and developers had then no other choice to fall back on cookies within apps. Another way to avoid Apple "iAd".
In a web browser, it is very easy today to disallow cookies. But what about within an application ? There is no way if the developer does not provide a setting for this or worse if the cookie is used without the user's consent.
With this new rule, the developers have put in place tracking cookies within their iOS application have works to do. They will simply have to rework or redesign their apps and / or even adopted the new iOS feature: Advertising identifier or their app may be rejected from the App Store.