I know this topic has been discussed here before, but I wanted to shed some more light on it. Recently I discovered a service called bluecava. They claim they are able to uniquely identify 99% of people, and their marketing it towards the advertising crowd. Take a look at their source code: http://ds.bluecava.com/V50/AL/BCAL5.js It's really nothing more than EFF's Panopticlick, however it's interesting to see that they are storing a device ID (aka fingerprint) based upon the information they retrieve. Check out their advisory board as well, some pretty prominent people - http://www.bluecava.com/about/advisory-board/
If I test my product on a population of internet consumers with a sample of say 40 users. Let us also assume these 40 users do not take any precautions while online and my product tracks them all. I can say my product tracks 100% of online users. (I know its not that skewed in a real world environment but still not far off). Marketing hogwash aside their product simply builds a persistent fingerprint for a device by examining factors such as the device’s software (OS), fonts, screen size, browser plugins, time zones and other data. This is simple finger printing 101 and nothing too concerning. It is also how they can claim to track users without cookies. I can see tablets and smartphones being harder to protect from fingerprinting, however with computers creating a non-unique finger print is very easy. One big way to mitigate this tracking product is simply to disable javascript on untrusted sites. You can also go a step further and use a generic browser configuration with anonymizing services. My source? I deal with many vendors and 3rd party companies promising me the moon and then some.
