The ‘Evercookie’ is a 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. A researcher in South Africa took a look at the way the 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 than the standard version.
Source: https://threatpost.com/researchers-find-methods-kill-persistent-evercookie-101910/74586/

