Sites pulling sneaky Flash cookie-snoop • The Register
Many websites are using Flash-based cookies to track users, but often omit to mention this in their privacy policies.
US academics have documented the little-known tracking technology and its use in practice in a paper called Flash Cookies and Privacy. Browser-based cookies constitute a well understood and widely deployed technology that poses serious questions about privacy, depending on its usage.
What’s far less well known is that Adobe Flash software also features cookies that can be used in much the same way as HTTP cookies. Flash cookies can be used for storing the volume level of a Flash video but the technology can also be used as “secondary, redundant unique identifiers that enable advertisers to circumvent user preferences and self-help”, the academics warn.
A significant percentage of websites including federal government sites use this Flash-based technology to track users, the researchers discovered. The technology is sometimes used as a means to “undelete” the information in browser-based cookies that a user might have thought they had cleared from their system when they deleted their browsing history, the academics explain.
Anti-tracking tools effective in blocking Flash-based cookies are far from widespread. Cookies can be deleted in Flash player itself, but this is a separate process from deleting them in a browser.
You can control these cookies by using the Flash player Settings Manager or by using Steelworx Flush Flash
via Sites pulling sneaky Flash cookie-snoop • The Register.
