How Your Device’s Battery Life Can Be Used to Track Your Online Activities

Admit it, it’s happened to you: you’ve casually searched for a specific product or service online, only to find persistent ads for it following you around every subsequent webpage you visit. Surprising, isn’t it, when digital heavyweights like Facebook and Google individuals deliver adverts personalized to your search history? On one hand, it’s impressive advertising efficiency; on the other, it’s an invasion of your privacy. This has led many of us to click ‘delete cookies’ and activate private browsing settings to avoid such targeted harassment. Fortunately, browsers like Opera have also responded by introducing ad blocking features, much to the despair of advertisers.

Yet, even as we fight back against targeted advertising, researchers are finding new ways for advertisers to keep tabs on our online habits. Steven Englehardt and Arvind Narayanan of Princeton University recently unveiled one such mechanism in their paper Online tracking: A 1-million-site measurement and analysis. According to their research, advertisers might be able to stalk you using the HTML 5 Battery Status API, a seemingly-innocuous function designed to save your device’s battery life.

In essence, the HTML 5 Battery Status API is a platform that allows sites to send you power-efficient versions of their content based on your device’s battery life. But in the wrong hands, it could also allow your online movements to be tracked. According to W3C, the API is intended to help web developers offer better battery usage and avoid causing unnecessary battery drain. However, it also warns of the adverse impacts if misused.

Where this becomes problematic is in the case of targeted advertising. Imagine being sent updates or ads based on your battery life, a parameter over which you have very little control. According to The Next Web, users were more prepared to pay surge prices while booking cabs on Uber when their phone battery was low, just to avoid getting stranded. Consequentially, our dependency on our devices and the dread of a dying battery might make us susceptible to manipulation if our battery life information is accessed by unwelcome entities.

Don’t despair, there’s light at the end of the tunnel – for Firefox users, at least, says HackRead. According to them, it’s currently possible to disable the battery status API on Firefox, and other browsers may soon follow suit. After all, our online privacy should remain in our control, not in the hands of advertisers or any opportunistic entities.