I was going in as "Yeah no, that's paranoia right there". Nope. Why the fuck did HTML5 allow tracking of ANY device metric beyond it's reported browser ID? That's sketchy beyond all belief.
Honestly, I'm quite paranoid myself and it probably wouldn't have occurred to me that such a nice little feature could pose a risk to the users' privacy... Let's see if and how the W3C responds to this.The battery status API is currently supported in the Firefox, Opera and Chrome browsers, and was introduced by the World Wide Web Consortium (W3C, the organisation that oversees the development of the web’s standards) in 2012, with the aim of helping websites conserve users’ energy. Ideally, a website or web-app can notice when the visitor has little battery power left, and switch to a low-power mode by disabling extraneous features to eke out the most usage.
Agreed. It's in times like these that I'm glad my phone is a bit outdated - it still uses whatever browser originally shipped with Android 4.11 I think, and is most often too underpowered to actually use it.