Facebook’s marketing technologies may target a particular person, according to researchers

According to a new study published by a group of academics and computer scientists from Spain and Austria, you can use Facebook’s targeting capabilities to deliver an ad from a digital marketing company to a single person provided you know enough about the interests Facebook’s algorithm gives them.

The study, titled “Unique on Facebook: Formulation and Evidence of (Nano)targeting Individual Users with Non-PII Data,” offers a “data-driven approach” that establishes a measure that indicates the likelihood that a Facebook user may be individually recognized based on the ad platform’s preferences.

The researchers show how they were able to utilize Facebook’s Ads management tool to target a lot of ads such that each one only reached one specific Facebook member.

The study raises new concerns about the potentially harmful uses of Facebook’s ad targeting tools, as well as broader concerns about the legality of the tech giant’s personal data processing empire, given that the information it collects on people can be used to uniquely identify individuals, even if only based on their interests.

The findings may raise pressure on politicians to prohibit or phase out behavioral advertising, which has come under fire for years due to worries that it causes a slew of personal and social problems. At the very least, the research appears to be fueling calls for more rigorous checks and balances on how such intrusive techniques are deployed.

The findings also highlight the importance of independent research being able to investigate algorithmic adtech — and should put pressure on platforms not to restrict access to academics.

Facebook interests are personal information

“The results of our model reveal that the four rarest interests or 22 random interests from the interests set FB [Facebook] assigns to a user make them unique on FB with a 90% probability,” write researchers from Madrid’s Carlos III University, Graz University of Technology in Austria, and the Spanish IT Support Services firm GTD System & Software Engineering, highlighting one key finding — that hav

“To the best of our knowledge, this is the first study that addresses individuals’ uniqueness in the context of a user base on the order of the global population,” they continue, referring to the massive scale of Facebook’s data mining of its more than 2.8 billion active users (NB: The company also processes information about non-users, meaning its reach scales to even more internet users than are active on Facebook).

According to the authors, the article is the first proof of “the feasibility of systematically leveraging the Facebook advertising infrastructure to execute nano targeting based on non-PII [interest-based] data.”

There have been previous debates about Facebook’s ad platform serving as a conduit for one-to-one manipulative messages, such as this 2019 Daily Dot article about a company called the Spinner selling a “service” to sex-frustrated husbands to target psychologically manipulative messages at their wives and girlfriends. On the subjects’ Facebook and Instagram feeds, the provocative, subliminally deceptive adverts would appear.

The study report also mentions a 2017 event in British politics, when Labour Party campaign leaders allegedly used Facebook’s Custom Audience ad-targeting feature to “draw the wool over the eyes” of former leader Jeremy Corbyn. However, the targeting in that case was not limited to Corbyn; it also included his colleagues and a few associated media.

The team shows that using Facebook’s Advertisements Manager tool, they can target ads to just one Facebook user, a technique they call “nanotargeting” (as opposed to the current adtech “standard” of microtargeting “interest-based” advertising at groups of users).

“We run an experiment through 21 Facebook ad campaigns that target three of the authors of this paper to show that, if an advertiser knows enough interests from a user, the Facebook Advertising Platform can be systematically exploited to deliver ads exclusively to a specific user,” they write, adding that the paper provides “the first empirical evidence” that one-to-one/nanotargeting can be “systematically exploited”.

The interest data they utilized for their research came from 2,390 Facebook users who had installed a browser extension they built before January 2017.

The Data Valuation Tool for Facebook Users addon scanned each user’s Facebook ad preferences page to gather their interests and provide a real-time estimate of the income they produce for Facebook based on the ads they see when surfing the network.

While the researchers’ trials investigating whether one-to-one targeting is possible using Facebook’s ad platform took place last year, the interest data was collected before that.

“We’ve created nanotargeting ad campaigns targeting three authors of this study in particular,” they say as they go through the results of their testing. “We put our data-driven approach to the test by building customized audiences for each targeted author using a mix of 5, 7, 9, 12, 18, 20, and 22 randomly picked interests from FB’s list of interests.

“From October to November 2020, we launched a total of 21 ad campaigns to show that nanotargeting is a reality today.”