Modern online ad with banners has transformed into exact science. Using cookie and social networks advertisers keep track of user’s online activity. Thanks to it ads can be targeted according to the user service class.
There are many ways for staying anonymous but in spite of it forward-minded advertisers can keep track with the help of battery charge. The last update of HTML5 contains special API that allows defining battery status. Requiring the information about battery status the site can be modified according to it. For instance, webpages can be shown in simplified form if battery charge level is low. API receives about 14 million of possible combinations such as the battery charge level to remain and approximate time to complete battery discharge.
If the site identifies two connections with one-to-one battery status, most probably they belong to the same user. It implies it may be singled out even using VPN or private mode.
Two researchers from Princeton University used modified browser for gathering scripts that keep tracks user’s activity. They found out two scripts that use interaction between API and battery for user’s device identification. It can be carried out at current version of popular browsers Firefox, Opera, Chrome.
Moreover, there’s an anxiety concerning the level decrease of anonymity on the Internet using the data about battery status.