Facebook has announced that it’s teaming up with four of the world’s 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. Here’s how to stop them. In practical terms, this type of targeting means that limiting how much information you put on Facebook is not enough to limit how ads are targeted to you on Facebook. Your interests, age, shopping history (including offline), web browsing, location, and much more could be stored by these data brokers and utilized to market to you.

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