Apple has reportedly started enforcing an App Store rule regarding location data more stringently. According 9to5mac, the tech giant has already removed a number of apps from the Store that share users' location to third parties without their explicit consent. In the letter it sent to the affected developers, Apple told them their applications didn't comply with Legal sections 5.1.1 and 5.1.2 of the App Store Review Guidelines. Those sections state that apps must not transmit "user location data to third parties without explicit consent from the user and for unapproved purposes."
Apple also told them they need to remove any code, framework or SDK used for location data collection and third-party sharing before their apps can be listed on the Store again. As 9to5mac noted, Cupertino has started cracking down on apps that violate its location data rules just before the EU's General Data Protection Regulation law takes effect on May 25th.
Whether Apple is truly doing this to comply with GDPR is unclear -- we've reached out to the company and will update this post when we hear back.
You can see Apple's whole letter below: