Source: Online tracking: A 1-million-site measurement and analysis

A very solid paper on how you are being tracked online. I had known about Font fingerprinting before (as the list of fonts you have installed is actually pretty unique), but using audio filter fingerprinting, or web rtc to get a list of ip addresses you can reach, is pretty novel. And a bit scary.

Which is all another good reason to install Ad Blocking software today. uBlock is my current favorite.