"Data we collect automatically: Your IP address and mobile device identifiers (such as your device or advertising ID). Data about your device, such as device name and operating system, browser type and language, internet service provider, and mobile carrier. We may also collect and use your device identifiers to display and personalize in-game ads and serve behaviorally targeted advertising."
Supercell collects extensive device information including advertising IDs, device identifiers, OS details, browser info, ISP, and mobile carrier data, much of which is used for advertising rather than core game functionality.