According to Wikipedia super cookies are “automatically recreated after a user has deleted them. This is accomplished by a script storing the content of the cookie in some other locations, such as the local storage available to Flash content, HTML5 storages and other client side mechanisms, and then recreating the cookie from backup stores when the cookie’s absence is detected.”
Prevention
These browsers / browser add-ons have a privacy mode that may be able to prevent supercookies. Our list is being compiled and tested.
Remedies
Manual Removal
File locations
The default storage location for Local Shared Objects is operating system-dependent.
On Microsoft Windows NT 5.x, they are stored in:[19]
%APPDATA%\Macromedia\Flash Player\#SharedObjects\
%APPDATA%\Macromedia\Flash Player\macromedia.com\support\flashplayer\sys\
On Microsoft Windows NT 6.x, they are stored in:[19]
%APPDATA%\Macromedia\Flash Player\#SharedObjects\
%APPDATA%\Macromedia\Flash Player\macromedia.com\support\flashplayer\sys\
On Mac OS X, they are stored in:
~/Library/Preferences/Macromedia/Flash Player/#SharedObjects/
~/Library/Preferences/Macromedia/Flash Player/macromedia.com/support/flashplayer/sys/
On Linux or Unix, they are stored in:
~/.macromedia/Flash_Player/#SharedObjects/
~/.macromedia/Flash_Player/macromedia.com/support/flashplayer/sys/
For Linux and Unix systems, if the open-source Gnash plugin is being used instead of the official Adobe Flash, they will instead be found at:
~/.gnash/SharedObjects/