Disabling cookies may not be the answer to controlling your online identity. Regardless of whether you have cookies enabled or not, Web sites collect certain amounts of operational information about your browser. The Electronic Frontier Foundation has detailed how companies can use browser-configuration information to identify users, and also launched a new project, Panopticlick, aimed at testing just how useful this type of data is for tracking people.
Once the sites collect these browser "fingerprints," then according to the EFF, those sites can theoretically recognize some visitors upon their return regardless of whether they still have their cookies. Additionally, a technology expert with EFF says that sites that identify a returning browser based on the configuration data -- or, perhaps, a combination of configuration data and IP address -- can then restore any cookies previously associated with that browser.
Utilization of technologies that effectively overrides the end user's choice of what, and how much, information to make available is inviting future regulation and may be violating some existing privacy regulations.
MediaPost - Flash Cookies Could Become Hot-Button Privacy Issue