There are plenty of times when sharing your location (on an Android device) is obvious. Naturally, we are referring to checkins, whether they be with Facebook or Foursquare or one of the many other services available. But according to a recent report coming from the Electronic Frontier Foundation (EFF) -- your Android device may also be sharing your location without you really knowing.
The EFF is pointing towards WiFi. Specifically, with the names of WiFi networks that you have been connected to. The EFF claims this issue is affecting devices running Android 3.1 Honeycomb and later. This goes to a feature called Preferred Network Overload (PNO) which the EFF describes as being one that is "supposed to allow phones and tablets to establish and maintain Wi-Fi connections even when they’re in low-power mode (i.e. when the screen is turned off)."
Essentially, this means your device could be broadcasting the names of networks you've visited. The other details here mention how this only seems to be happening when the device screens are turned off. To that point, the EFF mentioned how "many of the phones" they tested were able to "broadcast the names of networks they knew about when their screens were turned off."
This basically means you could be giving up details on places you've visited -- provided those places use the business name for the WiFi network name and you connected to the network during your visit. Seems to be a small item to worry about, but we suspect those feeling overly worried could take issue. The good news is there is a workaround available and that includes going into your phone’s “Advanced Wi-Fi” settings and adjusting the “Keep Wi-Fi on during sleep” option to “Never”.
The catch here -- this could cause a small increase in battery usage and data usage. All that having been said, the EFF has notified Google, who responded with a statement about how they "take the security of our users' location data very seriously" and how they "are still investigating what changes are appropriate for a future release."