EFF: “Facebook has announced that its teaming up with four of the worlds largest corporate data brokers to enhance the ad experience for users. Datalogix, Epsilon, Acxiom, and BlueKai obtain information gathered about users through online means (such as through cookies when users surf the web) as well as through offline means (such as through loyalty cards at supermarkets and product warranty cards). Through the new relationship with Facebook, companies will be able to display advertisements to Facebook users based on data that these data brokers have on individuals…We recommend you use a tool such as Ghostery (now available on Firefox, Safari, Chrome, Opera and Internet Explorer) or Abine’s DoNotTrackMe (available in Firefox, Safari, Chrome and Internet Explorer) or AdBlockPlus with EasyPrivacy Lists. See more comprehensive instructions in our 4 Simple Changes to Stop Online Tracking.”