Sometimes you check online for an item or service and after you simply close the site and probably log out. But the next time you’re on Facebook, Google or some other site that uses Google Ads and behold the stuff you searched for before you and you’re wondering how that happened. Now you may fee one of two ways; the first being surprise which may lead to you being either angry or pleased that the company is really personalising an ad to you so now it makes it easier to pay for the service now that you may be ready. But over the years this kind of targeted adverts have annoyed a majority of web users with Facebook and Google being the chief culprits since they both control 12 and 31 percent of the digital advert market respectively.
This has led users to over the years to either delete cookies and or activate private web browsing to avoid such targeted ads and now browsers like Opera to introduce ad blocking features to the chagrin of advertisers.
But now researchers (Steven Englehardt and Arvind Narayanan of Princeton University) in their paper Online tracking: A 1-million-site measurement and analysis now say there’s a way these advertisers can still get to you using HTML 5 Battery Status API. Before you get scared, this script allows a server send you its energy efficient version based on your device battery life. So if someone for example can have access to this information, it means your online activities can still be tracked.
According to W3 “the Battery Status API specification defines a means for web developers to programmatically determine the battery status of the hosting device. Without knowing the battery status of a device, a web developer must design the web application with an assumption of sufficient battery level for the task at hand. This means the battery of a device may exhaust faster than desired because web developers are unable to make decisions based on the battery status. Given knowledge of the battery status, web developers are able to craft web content and applications which are power-efficient, thereby leading to improved user experience. Authors should be aware, however, that a naïve implementation of this API can negatively affect the battery life.
The Battery Status API can be used to defer or scale back work when the device is not charging in or is low on battery. An archetype of an advanced web application, a web-based email client, may check the server for new email every few seconds if the device is charging, but do so less frequently if the device is not charging or is low on battery. Another example is a web-based word processor which could monitor the battery level and save changes before the battery runs out to prevent data loss.”
The long and short of it is that a company can quickly send you an update or ad based on your battery life which you really don’t have much control over. According to The Next Web for example, Ubers were more willing to pay for surge prices in cases of low battery. Users will pay up to 9.9 times the normal fare not be stranded should their battery life run out before they are able to book a taxi. This and many more other services can be provided to you by companies who have access to your battery life information and guys there is another way you are being tracked.
According to HackRead, you can disable battery status API on Firefox as others mull the idea.