Facebook’s 2-Factor Authentication With A Phone Number Isn’t Only For Security, It’s Used For Ads

Facebook tricked you.
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A new paper published by Princeton University researchers has put forth some very disturbing ideas, detailed Gizmodo. One of the main theories is that Facebook tricked their users into thinking that two-factor authorization with a number was for security purposes only.

The paper, titled “Investigating sources of PII used in Facebook’s targeted advertising,” aimed at discovering why the ads on the platform are so accurately targeted. It turns out that Facebook compiled what people are calling a “shadow profile” for each person, which includes personal information that is gathered through some less-than-straightforward ways.

One of the ways is described as follows.

“[Researchers] found that when a user gives Facebook a phone number for two-factor authentication or in order to receive alerts about new log-ins to a user’s account, that phone number became targetable by an advertiser within a couple of weeks.”

Also, Facebook gathered information for shadow profiles whenever someone uploaded their contact information with the platform. People sometimes do this in order to find more friends on Facebook.

Even the researchers were surprised to find out that Facebook ads used information “that was not directly provided by the user, or even revealed to the user.” And most of all, the report indicates that users were convinced to share private information about their contacts without fully understanding the implications.

Facebook responded to the study’s findings, not disputing it but releasing this statement instead.

“We outline the information we receive and use for ads in our data policy, and give people control over their ads experience including custom audiences, via their ad preferences. For more information about how to manage your preferences and the type of data we use to show people ads see this post.”

The reason why your personal information, like your phone number, is so very valuable to advertisers is because it lets them conduct high-level targeted advertising. That means that they’re able to get their ad in front of the people who are most likely to buy their product, thus boosting their sales.

At the same time, Facebook benefits by providing this level of advertising, which can prove more successful than other channels. But if Facebook is utilizing information from people’s shadow profiles, and the information was obtained in sneaky ways, it puts the platform on blast.

Facebook’s vice president of ads Rob Goldman even said the following.

I think that many users don’t fully understand how ad targeting works today: that advertisers can literally specify exactly which users should see their ads by uploading the users’ email addresses, phone numbers, names+dates of birth, etc.”

If you’re bothered by this, you can check out your “ad preferences” page. There’s a list of “advertisers you’ve interacted with,” which will show you who has your contact information.