What’s scary is all of the ways they can track you even without your browser actively cooperating. For example, they can create an HTML5 canvas, render a bunch of shapes, and then probe individual pixels to get a read on your graphics card and drivers. The EFF has a very educational test you can subject your browser to in order to see how easy it is to fingerprint it based on these kinds of things.

And here I naively had been wondering before reading this article what was so inherently privacy invading about using fingerprints to unlock devices…