Two types of technology on your Android device are security risks: Bluetooth and NFC (near field communications). If you have these turned on, your phone can be hacked because you are basically walking around broadcasting a radio signal. People can even use these features to track you. Keep reading to learn more about the security threat that Bluetooth and NFC present and how to turn them off.
Bluetooth
In the past, Bluetooth was typically used only for hands-free headsets. It was awkward, so people did not often use it to transfer photos, etc. However, now Bluetooth has been updated to support what are called BLE (Bluetooth low energy beacons). Retailers have plans to use these to track you when you walk through their stores so that they can pitch advertising which is tailored just for you. The beacons needed to do that are not widely deployed yet in stores. However, with Bluetooth 4, a retailer will be able to track where you go and how much time you spend at any location in the store. For example, they will be able to see that you have spent time looking at a particular jacket, so they might offer you a discount over a TV monitor.
You could consider such tracking a privacy issue instead of a security one, but the older Bluetooth technology still works on your phone. The main issue with the older technology is that there are some security issues with it which can cause your phone to be hacked. Therefore, if you are not using Bluetooth, turn it off.
NFC
The NFC chip in your phone broadcasts a radio signal over a short distance like Bluetooth. Not all phones have it. The idea was that people would use this and the Google Wallet and other systems to make payments with their cell phones. There are competing standards in the industry as tech and credit card companies wrestle to see who will come out on top. For the same reason as above (i.e., the security risk that a hacker can use it to hack your phone), just turn it off.
Here is how to turn off both Bluetooth and NFC on Android 4.4.
Turn off Bluetooth
1. Go to Settings, and click Off next to Bluetooth.
Turn off NFC
1. Go to Settings, and select More. Then deselect NFC.