The German Advertising Federation, or ZAW, on Monday filed an antitrust complaint against Apple over the leading tech corporation’s rollout of the App Tracking Transparency (ATT) feature. The complaint claims that Apple was abusing its market power and, overall, violating antitrust law.

Apple launched the new feature through an update to its iOS operating system on Monday. This feature has garnered attention for its requirement that apps gain users’ permission before being able to track them and their activity across the web, limiting the reach and amount of impressions made to help cultivate targeted ads.

Many corporations, both domestic and international, have aired their grievances regarding the update feature. The advertising federation claims that it gives Apple a “one-sided advantage.” Facebook has also pushed back against this new feature as it relies heavily on targeted ads in order to increase impressions and user engagement. These corporations claim that it is harmful to small businesses as well as excludes competitors from getting access to commercially relevant data in the Apple ecosystem.

Apple responded to the complaint by stating:

A user’s data belongs to them and they should get to decide whether to share their data and with whom. With iOS 14.5, we’re giving users the choice of whether or not they want to allow apps to track them by linking their information with data from third parties for advertising, or sharing their information with data brokers.

The feature was originally slated to launch last September, but was postponed. Starting Monday, all apps submitted to the App Store must have the ATT enabled.