Mozilla and Standford Univesity develops the project Cookie Clearinghouse for managing third-party cookies. The plugin will not be available for Mozilla Firefox 22, since it is not stable enough.
Cookie Clearinghouse is a Do Not Track option, which will forbit the site to make any tracking.
This is what the new Mozilla Plugin does (from here):
“False positives. For example, say you visit a site named foo.com, which embeds cookie-setting content from a site named foocdn.com. With the patch, Firefox sets cookies from foo.com because you visited it, yet blocks cookies from foocdn.com because you never visited foocdn.com directly, even though there is actually just one company behind both sites.
False negatives. Meanwhile, in the other direction, just because you visit a site once does not mean you are ok with it tracking you all over the Internet on unrelated sites, forever more. Suppose you click on an ad by accident, for example. Or a site you trust directly starts setting third-party cookies you do not want.
Our challenge is to find a way to address these sorts of cases. We are looking for more granularity than deciding automatically and exclusively based upon whether you visit a site or not, although that is often a good place to start the decision process.”
But the big sites use different servers to deliver content, usually photos to the users and so, with this plugin, the cookies from the site visited by the user will be accepted and the ones from the sites that are used to deliver content will be discarded.
The Plugin will use an “allow list” and a “block list”, created by the Mozilla developers. I think it will not be a big success after the release, but after the two lists will be improved, it will get a lot better.
Mozilla will release the new plugin on the 2nd of July, at an event dedicated for it. To my mind, the best reason to use this plugin is that social networks like Facebook, Google+ and Twitter will not be able to track your internet activity by their scrits on third party sites.