"If you choose to sign up using third-party services such as Google, Facebook, or Apple, we may receive additional information from these platforms, including your profile picture, friends list, and basic demographic information. We automatically collect certain technical information about your device including unique device identifiers, IP address, and mobile network information."
The combination of unique device identifiers, IP addresses, third-party social login data (including friends lists), and sharing with advertising providers enables cross-service tracking and profiling of users.