The Evercookie is a simple method for forcing a user's machine to retain browser cookies by storing the data in a number of different locations. The method also has the ability to recreate deleted cookies if it finds that the user has removed them. Created by Kamkar as a demonstration of a way that sites could use to persistently track users even after they clear their browser cookies, the Evercookie has drawn the attention of a number of other researchers who have spent some time looking for methods to defeat it. A researcher in South Africa took a look at the way the the Evercookie works on both Safari on the desktop and on mobile devices, and found that it can be undone in some circumstances. However, he also found that the mobile version of Safari fares far worse in its handling of the Evercookie than the standard version does."
Link to Original Source