Flash Cookies and What You Don’t Know

Apple Snow LeopardIf you have been browsing the internet for any period of time, I’m sure you have heard of cookies. Even though you may not be entirely sure what they do, you certainly know how to delete them. Right?

Cookies are files websites save on your computer that contain information about you. There are several legitimate purposes for these files such as remembering your login information so you don’t have to sign in every time you visit a site, keeping up with cart information as you shop online and in some cases online security such as banking sites.

With the good also comes the bad. A quick search on Google for tracking cookies will return page after page of articles on this topic. A tracking cookie will monitor your movement around the internet and will phone home to let its authors know what you are doing online. With this information they will taylor their advertising on affiliate sites so that you only get ads for what they believe interests you or they will sale this information to other advertisers.

“So what’s the big deal? My browser is set up to delete cookies at regular intervals and I don’t allow them from third party sites.”

Well here is a little fact that you may not know. The same technology that powers streaming video, online games, and animated movies, has the ability to set these cookies as well. The technology I am referring to is the flash plugin, currently developed by Adobe. These “special” cookies are not created or treated the same way as the cookies that we have all come to know and love. In fact your browser has, on its own, no control over these cookies at all.

To illustrate this point, clear your browser cookies and then take a look in the following location(s):

  • Windows: Under your current user’s Application Data directory, click on Macromedia\Flash Player\#SharedObjects and Macromedia\Flash Player\macromedia.com\support\flashplayer\sys.
  • Mac OS X: ~/Library/Preferences/Macromedia/Flash Player/#SharedObjects/[package ID of your app]/ and ~/Library/Preferences/Macromedia/Flash Player/macromedia.com/support/flashplayer/sys/
  • GNU-Linux: ~/.macromedia

Using your browser to clear cookies had no effect whatsoever on the flash cookies. That possibly and probably means that your actions are still being tracked as you surf the net. What’s more, flash cookies have the ability to restore the normal cookies that your browser just deleted.

“So what can I do about these cookies? You said earlier that my browser on its own could not delete these cookies, what does that mean?”

A developer going by the name of NettiCat, has developed an addon for Firefox called Better Privacy that will do the dirty work for you. This addon allows you to clear these cookies when you open or close your browser, at regular intervals and manually.

Now feel free to go trash those stale cookies and be on the lookout for them popping up again.

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4 Responses to “Flash Cookies and What You Don’t Know”

  1. Speaker-to-Animals October 13, 2009 at 11:25 pm #

    A quibble, I know, but “its” as possessive pronominal adjective is spelled without an apostrophe. The ONLY acceptable usage of “it’s” is as a contraction of “it is.”

  2. safety October 13, 2009 at 11:37 pm #

    Duly noted and corrected Speaker-to-Animals. I hope you found this article interesting and thanks for stopping by.

  3. Allister Frau October 14, 2009 at 12:31 am #

    Interesting observation. A lot of sites embed a whole on of flash and you can never be too sure what it’s doing.

  4. safety October 14, 2009 at 12:53 am #

    I have found that on Linux and OS X, you can change the permissions on the folders to stop flash from writing any cookies.

    In OS X you would use:
    chmod -R -w \#SharedObjects/ macromedia.com/

    So far, I have not run into any sites that display incorrectly or refuse to work because of this change.

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