I'd recommend that everyone download and install Flashplayer 10 and read All the info on the following page!
http://www.adobe.com/products/flashplayer/security/
Then go to the "Flashplayer Settings Manager page" at
http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager.html
Then go to the "Website Privacy Settings Panel", on this page, and see what web sites have been storing trackable flashcookies on your computer and update your security settings as described on both of these pages.
Then go to the "Global Storage Settings Panel" on the Settings Manager and uncheck the "Allow third party Flash content to store login information and other data on your computer" check box.
I was amazed what had been stored without my knowledge. Just goes to show you what has been in use by a company, Abobe, for quite so time, since at least Flashplayer8, until now. Talk about closing the barn door after the horses got out!