A few months ago The Washington Post reported that Facebook collects ninety-eight data points on each of its nearly two billion users. Among this ninety-eight are ethnicity, income, net worth, home value, if you are a mom, if you are a soccer mom, if you are married, the number of lines of credit you have, if you are interested in Ramadan, when you bought your car, and on and on and on.

How and where does Facebook acquire these bits and pieces of one’s personal life and identity? First, from information users volunteer, like relationship status, age, and university affiliation. They also come from Facebook posts of vacation pictures and baby pictures and graduation pictures. These do not have to be photos one posts oneself: Facebook’s facial recognition software can pick you out of a crowd. Facebook also follows users across the Internet, disregarding their “do not track” settings as it stalks them. It knows every time a user visits a website that has a Facebook “like” button, for example, which most websites do.

The company also buys personal information from some of the five thousand data brokers worldwide, who collect information from store loyalty cards, warranties, pharmacy records, pay stubs, and some of the ten million public data sets available for harvest. Municipalities also sell data—voter registrations and motor vehicle information, for example, and death notices, foreclosure declarations, and business registrations, to name a few. In theory, all these data points are being collected by Facebook in order to tailor ads to sell us stuff we want, but in fact they are being sold by Facebook to advertisers for the simple reason that the company can make a lot of money doing so.

Not long ago I dug into the depths of Facebook to see what information it was using to tailor ads for me. This is a different set of preferences and a different algorithm—a set of instructions to carry out an operation—than the one Facebook uses to determine which stories it is going to display on my so-called news feed, the ever-changing assortment of photos and…