I read the "Watch out for hidden cookies" on the magazine home page. I wonder how many realise Yahoo already operate such a system, calling the cookies "Web Beacons" It is an opt out policy, which means you have to find the web page to opt out. There is neither a mention or a link to this on the current Yahoo home page. Instead you have to navigate to the Yahoo privacy centre: click here Then scroll about half way down to the Cookies sub heading. There you will find the first mention of Web Beacons. If you click on "Web Beacons" you get to a page which explains a little. There is a link to an opt out page on the left click here The system is not browser dependant, which means each browser you use requires you to opt out. In addition every person who has an account on the computer will have to do this for each browser they use. You will have to repeat this for every computer you use. Personally I would like to be regulations in force to make it an opt in system, which would make it much more transparent and easier to deal with.