NSA Cybersecurity Information: “Mobile devices store and share device geolocation data by design. This data is essential to device communications and provides features—such as mapping applications—that users consider indispensable. Mobile devices determine location through any combination of Global Positioning System (GPS) and wireless signals (e.g., cellular, wireless (Wi-Fi®1), or Bluetooth®2 (BT)). Location data can be extremely valuable and must be protected. It can reveal details about the number of users in a location, user and supply movements, daily routines (user and organizational), and can expose otherwise unknown associations between users and locations. Mitigations reduce, but do not eliminate, location tracking risks in mobile devices. Most users rely on features disabled by such mitigations, making such safeguards impractical. Users should be aware of these risks and take action based on their specific situation and risk tolerance. When location exposure could be detrimental to a mission, users should prioritize mission risk and apply location tracking mitigations to the greatest extent possible. While the guidance in this document may be useful to a wide range of users, it is intended primarily for NSS/DoD system users…

Location data from a mobile device can be obtained even without provider cooperation. These devices transmit identifying information when connecting to cellular networks. Commercially available rogue base stations allow anyone in the local area to inexpensively and easily obtain real-time location data and track targets. This equipment is difficult to distinguish from legitimate equipment, and devices will automatically try to connect to it, if it is the strongest signal present…”