Adobe's Flash can be used to track you on the Web, even if you try to delete all cookies. Here's how to stop Flash from doing that.
Al Fasoldt's reviews and commentaries, continuously available online since 1983


How to block a sneaky Web-tracking ploy from Adobe's Flash

Sept. 19, 2010

By Al Fasoldt
Copyright © 2010, Al Fasoldt
Copyright © 2010, The Post-Standard

   If you've watched a video on YouTube or any other video-sharing site, you've used Flash. It's a cool way to show movie clips and other animations on your computer.
   But Adobe, the company behind Flash, built a not-so-cool tracking mechanism into Flash that can be used to keep tabs on what you do on the Web. It's bad news for anyone who values privacy.
   It's especially bad news if you care about cookies. Many users set up their Web browsers to allow only limited cookies (tiny text files that track what you're doing). A good policy is to reject cookies that come from outside the site your browser is on, which usually blocks advertising cookies and the like.
   But Flash cookies, Adobe's privacy killer, can't be controlled from your browser's Options or Preferences menu. Why not? Because they're not collected by your Web browser. It doesn't even know about them. They're stored by your Flash player -- by Adobe's Flash software, outside the reach of your browser.
   What's more, Flash cookies aren't limited to a few words of text like regular browser cookies. Flash cookies can hold 25 times as much information. Any Web site that wants to use Flash cookies can do so easily without your knowledge, too. And don't think you're safe because you don't watch videos; all sorts of animations in advertising are based on Flash, too. Experts say 98 percent of all personal computers have Flash players installed.
   So it's time to fight back.
   Adobe created a way for you to opt out of Flash cookies, but all the folks I've talked to who've tried using Adobe's method have said the same thing -- it's confusing beyond belief.
   I checked it and agree. I'd have to guess Adobe doesn't actually want you to opt out. If you want to see this monstrosity for yourself, go to this site: http://tinyurl.com/5dn2k. (The actual URL is so complicated I had to make an alias. C'mon, Adobe.) And then go here: http://tinyurl.com/6lrqv. (Yes, there are TWO confusing Adobe sites you have to go to.)
   Here's a better method. If you're using Windows, download and install the free Flash Cookie Cleaner from www.flashcookiecleaner.com. If you're using a Mac, download and install the free Flush.app from http://tinyurl.com/q6m6r6. (I've shortened this URL and the one below.)
   NOTE: Flush didn't work on my main Mac. To get rid of Flash cookies on a Mac manually, do this:
   -- Open a Finder window showing your Home folder. (The Home folder is the one with your logon name.)
   -- Double click on the Library folder inside your Home folder.
   -- Press Cmd-F and type "#SharedObjects" just as I've written here, without the quotation marks. (Remember that there are no spaces.)
   -- If you see anything listed in the Finder window called #SharedObjects, click once on it and drag it to the Trash. Then empty the Trash.
   Another way to zap Flash cookies, if you use Firefox on Windows or a Mac, is the free Better Privacy plugin. Get it from http://tinyurl.com/325oezm.