All WiFi-capable devices broadcast a unique ID called a media access control (MAC) address, when they're looking for networks, and so long as WiFi is enabled they are always looking for networks. This means that if you walk around carrying a mobile device with WiFi enabled, then you are broadcasting your own unique radio beacon and it's easy to track your movements.
This GPS and Location-based information can be useful for the following:
•More accurate directions when using maps and directions.
•Customized information from shopping apps (showing nearest locations, deals in your area, etc.).
•Safety and peace of mind from “Find my Friends” (iOS) or “Guardian” (Windows) apps. Apps like these can enable families to be aware of each other’s locations. Guardian enables users to call for help through an 'SOS' alert button and also connect to security agencies, police and hospitals easily in times of crisis.
This is not a comprehensive list, however it does show these features offer wonderful benefits. But you want to make sure you are in control of the information you are broadcasting to the cyber world.
Is your smartphone broadcasting your movements when you shop?
Some retailers are taking advantage of the signal sent by WiFi-enabled devices. You might see a sign in a shopping center that reads: “To provide a better shopping experience for our customers we anonymously survey the movement of mobile phones to help show us how the centre is used. No personal data is recorded at any time.”
This raises some security concerns such as claims the collected data would be de-identified and de-personalized, but “anonymous” data can still provide a lot of information and similar to other cookies and tracking methods, retailers want to use location information to produce personal profiles and targeted advertising. But if retailers can use this information, so can phishers and social engineers.
This movement tracking is even speading to your car, with BMW developing similar technology which will allow businesses to market their products through the German car maker’s built-in satellite navigation system.
The easiest way to defeat the anonymous tracking -- simply turn off WiFi and Bluetooth on your mobile device when away from home.
Another tracking method expanding rapidly is Google’s Location History Browser, which gives a minute-by-minute map of your life.
Location History allows Google to store a history of your location data from all devices where you are logged into your Google Account and have enabled Location Reporting. So if you have a device that uses a Google-driven operating system (e.g. an Android phone or tablet), there’s a good chance you had to answer a prompt about location history during device set-up. And if you opted-in to this tracking, Google might have a pretty comprehensive history of where you’ve been.
This long-term tracking of location data can give deep insight into your habits and patterns. On one hand, this can be eerie or even creepy. But it can also be kind of fun and nifty to review.
To get around this, Google allows you to manage your privacy in two ways: either by clearing your history, or by opting out of the service altogether. Learn how here: Manage Location in Google Settings
In Summary: Some tips to own your Online Presence
•When you’re not at home, consider turning off WiFi and Bluetooth. This will both conserve your device’s battery life and also protect you from continually broadcasting your location. Turn it on again when you want to connect to a wireless network.
•Review the privacy settings on your devices. Be intentional about the apps you allow to access your location. Consider turning permissions off when you are not actively using an app.
•Periodically clear your history. This certainly applies to location history, but it applies to other kinds of history too -- this site offers practical tips for managing brower history and other private data