The upcoming iOS 9 has already brought rumours of support for ad blockers on Safari, and now Apple is introducing another wrinkle for those hoping to advertise to consumers using their latest operating system.

According to The Information, a private session at WWDC earlier this month saw Apple announce to developers that it would be rolling out a new policy that restricts advertisers from obtaining app-download data.

Many advertisers, especially those dealing with app-download ads, examine what apps a user has previously downloaded in order to determine which ads are most relevant to you and most likely to result in a click. Advertisers who do this include Facebook and Twitter, as well as a large number of others.

However, iOS 9s focus on privacy has led to the company cracking down on the practice, with some at Apple comparing it to looking at your internet browsing history and saying that it should be private.

The API that enables such app-download data to be accessed is designed to make it easier for apps to communicate with each other, but Apple has said that companies are using it in an unintended way to access this information.

Startup iHasApp, which sold download data to other developers, shut down in May after being scolded by Apple for “using public APIs in a manner not prescribed by Apple.”