More than half of the internet’s top websites use a little known capability of Adobe’s Flash plug-in to track users and store information about them, but only four of them mention the so-called Flash Cookies in their privacy policies, UC Berkeley researchers reported Monday.
Unlike traditional browser cookies, Flash cookies are relatively unknown to web users, and they are not controlled through the cookie privacy controls in a browser. That means even if a user thinks they have cleared their computer of tracking objects, they most likely have not.
Adobe’s Flash software is installed on an estimate 98 percent of personal computers, and has been a key component in the explosion of online video, powering video players for sites such as YouTube and Hulu.
Websites can store up to 100K of information in the plug-in, 25 times what a browser cookie can hold. Sites like Pandora.com also use Flash’s storage capability to preload portions of songs or videos to ensure smooth playback.
Users who want to control or investigate Flash cookies have several options, according to reader Brian Carpenter:
* Better Privacy extension for Firefox -
* Ccleaner - http://www.ccleaner.com
Where to find these flash cookies:
* Windows: LSO files are stored typically with a “.SOL” extension, within each user’s Application Data directory, under Macromedia\FlashPlayer\#SharedObjects.
* Mac OS X: For Web sites, ~/Library/Preferences/Macromedia/FlashPlayer.
For AIR Applications, ~/Library/Preferences/[package name (ID)of your app] and ~/Library/Preferences/Macromedia/FlashPlayer/macromedia.com/Support/flashplayer/sys
* GNU-Linux: ~/.macromedia