Mark Wilson writes: Is the battery in your smartphone being used to track your online activities? It might seem unlikely, but it's not quite as farfetched as you might first think. This is not a case of malware or hacking, but a built-in component of the HTML5 specification. Originally designed to help reduce power consumption, the Battery Status API makes it possible for websites and apps to monitor the battery level of laptops, tablets, and phones. A paper published by a team of security researchers suggests that this represents a huge privacy risk. Using little more than the amount of power remaining in your battery, it is possible for people to be identified and tracked online. As reported by The Guardian, a paper entitled The Leaking Battery by Belgian and French privacy and security experts say that the API can be used in device fingerprinting.