Consumer Advocates Seek a ‘Do-Not-Track’ List - New York TimesThis idea of a "do not track" list is very interesting but also very problematic. Right off the bat is the problem of how a website would know NOT to track you. If the default is that you be tracked, you would need to pass some kind of token to every website that you wish not to track you. This would probably be a cookie, which would would be vulnerable to deletion every time a user clears her cookies. It also puts the responsibility on the user to keep track of all the websites which might track her information and maintain that preference across all of them.This is very different from the phone number based "do not call" list, where the marketer can check against a list of numbers they should not call. In this case, the user hits the website out of the blue, and the website needs to work out whether to track or not. One solution would be for there to be some kind of universal identifier that all websites could check against the list, but this is certainly replacing one kind of tracking with a much worse kind.This could all be avoided if the default was set to "do not track" and users could opt in. Of course, almost no one would bother to opt in to the targeted tracking. This is a problem because it is exactly this kind of targeted advertising that makes so many free Internet services possible right now. Without ad targeting the advertising revenue would likely be too low to make the services viable. As usual, I am in favor of the user controlled opt out of privacy technology, without requiring the consent or support of the tracking websites. If you don't want to be tracked, tools exist (like Anonymizer) to prevent that tracking. Just use them.