Taos, New Mexico, autumn 2012. At 18, Tina Porter has been on Facebook for four years. Duly briefed by her parents, a teacher and a therapist, she takes great care not to put contents – remarks on her wall, photos, videos – that could expose her in a unwanted manner.

Still. Spending about 30 hours a month on the social network, she has become as transparent as a looking glass. It will impact the cost of her health insurance, her ability to get a loan and to find a job.

Denver, Colorado, spring 2018. Tina is now 24. She's finishing her law degree at Colorado State University. She's gone through a lot: experimenting with substances, been pulled over for speeding a couple of times, relying on pills to regain some sleep after being dumped by her boyfriend. While Tina had her share of downs, she also has her ups. Living in Denver she never missed an opportunity to go hiking, mountain biking, or skiing – except when she had to spend 48 gruesome hours in the dark, alone with a severe migraine. But she remains fit, and she likes to record her sports performances on health sites – all connected to Facebook – and compare with friends.

Seattle, winter 2020. In a meeting room overlooking the foggy Puget Sound, Alan Parsons, head of human resources at the Wilson, McKenzie & Whitman law firm holds his monthly review of the next important hires. Parsons is with Marcus Chen, a senior associate at Narrative Data Inc; both are poring over a selection of CVs. Narrative Data was created in 2015 by a group of MIT graduates. Still headquartered in Cambridge, Massachusetts, the startup now helps hundreds of corporations pick the right talent.

Narrative Data doesn't track core competencies. The firm is more into character and personality analysis; it assesses ability to sustain stress, to make the right decision under pressure. To achieve this, Narrative Data is staffed with linguists, mathematicians, statisticians, psychologists, sociologists, neuroscientists. What they basically do is data-mining the social internet: blogs, forums, Twitter, and of course Facebook. Over the years, they've drawn a map of behaviours, based on language people use. Thanks to Narrative Data's algorithm, everyone aged above 20 can have his or her life unfolded like a gigantic electronic papyrus scroll. HR people and recruiters love it. So do insurance companies and banks.

Of course, in 2015 no one will be dumb enough to write on his Facebook wall something like "Gee, bad week ahead, I'm heading to my third chemotherapy session". But Narrative Data is able to pinpoint anyone's health problems by weaving together language patterns. For instance, it pores over health forums where people talk, openly but anonymously, about their conditions. By analysing millions of words, Narrative Data has mapped what it calls Health Clusters, data aggregates that provide remarkable accuracy in revealing health conditions. The Cambridge company is even working on a black program able to "de-anonymise" health forum members thanks to language patterns cross-matching with Facebook pages. But the project raises too many privacy issues do be rolled out – yet.

Tina Porter's CV popped up thanks to LinkedIn Expert, the social network's high-end professional service. LinkedIn, too, developed its own technology to data-mine resumés for specific competences. Tina's research on trade disputes between Korea and the US caught everyone's interest at Wilson, McKenzie. That's why her "3D Resumé" – a Narrative Data trademark – is on the top of the pile, that is displayed on a large screen in the meeting room.

Narrative Data's Marcus Chen does the pitch:

"Tina Porter, 26. She's what you need for the transpacific trade issues you just mentioned, Alan. Her dissertation speaks for itself, she even learned Korean..."

He pauses.

"But?..." Asks the HR guy.

"She's afflicted with acute migraine. It occurs at least a couple of times a month. She's good at concealing it, but our data shows it could be a problem," Chen says.

"How the hell do you know that?"

"Well, she falls into this particular Health Cluster. In her Facebook babbling, she sometimes refers to a spike in her olfactory sensitivity – a known precursor to a migraine crisis. In addition, each time, for a period of several days, we see a slight drop in the number of words she uses in her posts, her vocabulary shrinks a bit, and her tweets, usually sharp, become less frequent and more nebulous. That's an obvious pattern for people suffering from serious migraine. In addition, the Zeo Sleeping Manager website and the stress management site HeartMath – both now connected with Facebook – suggest she suffers from insomnia. In other words, Alan, we think you can't take Ms Porter in the firm. Our Predictive Workforce Expenditure Model shows that she will cost you at least 15% more in lost productivity. Not to mention the patterns in her Facebook entries suggesting a 75% chance for her to become pregnant in the next 18 months, again according to our models."

"Not exactly a disease from what I know. But OK, let's move on".

I stop here. You might think I'm over the top with this little tale. But the (hopefully) fictitious Narrative Data Inc could be the offspring of existing large consumer research firms, combined to semantic and data-mining experts such as Recorded Future. This Gothenburg (Sweden)-based company – with a branch in... Cambridge, Massachusetts – provides real-time analysis of about 150,000 sources (news services, social networks, blogs, government websites). The firm takes pride in its ability to predict a vast array of events (see this Wired story).

Regarding the "de-anonymising" the web, two years ago in Paris, I met a mathematician working on pattern detection models. He focused on locating individuals simply through their mobile phone habits. Even if the person buys a phone with a fake ID and uses it with great care, based on past behaviour, his/her real ID will be recovered in a matter of weeks. (As for Facebook, it recently launched a snitching program aimed at getting rid of pseudonyms – cool.)

Expanding such capabilities is only a matter of refining algorithms, setting up the right data hoses and lining up the processing power required to deal with petabytes of unstructured data. Not an issue any more. Moore's Law is definitely on the inquisitors' side.

– frederic.filloux@mondaynote.com