Travelers warned of automatic smartphone data sharing with foreign networks

When a smartphone is turned on abroad, it automatically sends identification data to the local mobile network, allowing operators to determine the user’s exact location. The Electronic Frontier Foundation (EFF) explains that this occurs as long as the device is powered and a SIM is present, even if the user never connects to a foreign carrier.

The EFF recommends disabling three settings before traveling: turn off Wi‑Fi and Bluetooth scanning that broadcast the device’s MAC address, restrict apps to approximate rather than precise location, and enable the “Limit Precise Location” (or similar) option that restricts location data to the operator‑level view only. Adjusting these settings can reduce digital footprints at hotels, cafés, airports and elsewhere while abroad.