Don’t like Facebook secretly tracking your online purchases and telling your friends what you bought? Users of the Firefox we browser can use an easy add-on that jams the beacon’s signal. Just install the BlockSite add-on, and then add http://*facebook.com/beacon/* as one of the blocked sites. Make sure to keep those asterisks in. If that sounds a little complicated, this step-by-step walk-through at Wikihow shows you how it’s done. Alternatively, you could also add the same url to AdBlockPlus, another Firefox extension.
How To Block Facebook's Beacon
By consumerist.com December 5, 2007