Privacy is one of the most important when it comes to browsing and most of the browsers have started implementing this feature. We had covered on how to enable tracking protection in IE9. Firefox 4 latest build has the feature of disabling behavioural tracking. The “Do Not Track” privacy feature enables users to prevent websites to opt-out of tracking. When this option is selected, a header will be sent signalling to websites that you wish to opt-out of online behavioral tracking.
To disable tracking, open Firefox options, click on the Advanced tab and select General sub tab. Under this tab check the box against “Tell web sites I do not want to be tracked”.
This will prevent websites from tracking and also in turn block all ads of websites which are cookie based.
More details available here.