Privacy at Risk?

I have been reading about privacy concerns related to Flash-based Local Shared Objects (LSO).  If you are interested privacy matters, I recommend you follow the above link or this one from Slashdot and read up.

LSO has been around for a while, and is intended to:

  • be used by Flash objects only
  • store structured data as an improvement to Cookies
  • store up to 100K of data
  • be controlled by end-users

You should also be aware of the new API for HTML5 because it will probably be used to achieve the same affect as LSO.  I should also mention Google Gears too.

LSO are not Cookies, so clearing Cookies from the browser does not get rid of them. This sounds scary, but LSO has not been reported as a privacy exploit (I apologize for the sensational title of this post). If you are concerned because of your private nature, here are some things you can do:

In order to see what LSOs are currently on your system, you can use an one of two applications provided by Macromedia.  You will find that clearing Cookies does not clear LSOs.  Of course, a Shift+Right Click within a webpage (on a Flash Object) will always bring up Preferences for that particular object.


Delete LSO objects in:

C:\Documents and Settings\%USERNAME%\Application Data\Macromedia\Flash Player\#SharedObjects

I also found a reference to CCleaner for Windows (being a Linux user, I have no experienced with this tool)


Delete the contents of:

/Users/username/Library/Preferences/Macromedia/Flash Player/#SharedObjects


/Users/[username]/Library/Preferences/Macromedia/Flash Player/*


Delete the contents of:





Install the Flashblock add-on (I tried it and it works)