(CNN) -- Apple is making a massive change to how developers can track your behavior.
The tech giant launched a features called "App Tracking" on it's IOS14.5 operating system, which runs on iPhones.
Users must now give explicit permission for apps to track their behaviors.
In the past apps have been allowed to track that data by default. Users could stop it, but they had to dig for settings that were often difficult to locate to turn tracking off in each app.
Many apps keep track of things like age, location and spending habits, then use that information to deliver targeted advertising. Some apps also sell the information to third parties.
Facebook is one of the most well-known collectors of such data. The social media platform frequently uses the information it collects to show users advertisements for products they are likely to be interested in purchasing.
Facebook warned investors back in August the new feature from Apple could hurt its business.