The opt-out cookie model is a joke. There are 90+ behavioral advertising companies, and consumers must opt-out of each one in order to just say no.
Tools like TACO help, but they simply do not scale. Each time a new advertiser hits the market, TACO must be updated to support its opt-out. As a result, the privacy community is always playing catch-up. It's time to change that.
A much better approach is for a universal opt-out header, which the user could select with a single preference, and which would then be communicated to all web sites that they visit. If the site is an advertising company, they will hopefully honor the opt-out, and if they're not, they can ignore it. No harm done.
This tool acts as an implementation of exactly this, much in the same way Firefox 4 will. After the add-on has been installed, Firefox will send the following header along with every new request (HTTP or HTTPS) to a web server:
Pre-1.0 versions of this add-on:
Version 1.0 of this add-on:
version 1.0 has changed to mimic the header supported by Firefox 4.0b11 and later, as well as the header sent by NoScript and recommended by donottrack.us
. The meaning of the two opt-out headers sent before are rolled up into this one, "DNT" header. If you use Firefox 4.0b11 or later, you don't need this add-on anymore!