Any media property that cares about traffic has installed Facebook, Twitter, and Google Plus buttons on its stories. Nominally, the easier we make it for you to share, the more likely you are to do so, and the greater the chance that you'll drive someone else to our website.

But there's a downside to these buttons, a University of Washington research team, explains.

Whenever you see one of these buttons, the tracker (e.g., Facebook or Google) that provides it knows that you are visiting the current site, even if you don't click the button and even if you have third-party cookies disabled. This tracking does not happen anonymously if you are logged in to (or in some cases have ever been logged in to) the tracker's site, since that tracker knows which account you're logged in with. This tracking is possible because of how browsers work: your cookies as well as the address of site you're viewing are sent to the tracker whenever one of these buttons is loaded.

To address this issue, Franzi Rosener, Yoshi Kohno and David Wetherall teamed up to build ShareMeNot, a Firefox plugin that stops the buttons from tracking you until you actually click on them. This is an important feature, too, because it preserves the part of the experience that most people want -- easy sharing -- while preventing the automatic tracking behavior that you might not want. This is an elegant, practical solution. Now if only more people knew about the problem.

You can download the add-on and check out the gory details at the ShareMeNot site.

Via Kevin Poulsen.