Android users, listen up! This alert is specifically for you.
If your Android gadget - phone or tablet - is less than three years old, it could be broadcasting your Wi-Fi connection location history to anyone that wants to listen.
The strange thing is that it only happens when your screen is off, and you are not connected to a Wi-Fi network.
Why is this happening?
When gadgets are trying to connect to a Wi-Fi network, they frequently display past connection names in an attempt to make a faster Wi-Fi connection. For example, if you visit a local coffee shop and use the Wi-Fi there, your gadget will store the connection information and broadcast it to connect to a known network a little faster.
The problem is that younger Androids can store and broadcast up to 15 Wi-Fi connections, which means that you can be tracked from your home to a store or business, your workplace, your church, and even travel destinations like airports and out of the country connections.
These stored locations aren't being broadcast in numbers like a router ID, either. Most of these locations are being displayed in full text (Tom's Bistro) and even when they aren't in full text, it's easy enough to look up the information online.
This problem has been traced back to Android 3.1 (Honeycomb) and a new feature called Preferred Network Offload (PNO). This feature is supposed to help maintain connections and find Wi-Fi connections when in low power mode, which explains why it only works when the screen is off.