When algorithms know almost everything about you, what is the point of a privacy screen?

NEW YORK – Maybe you are sitting on a subway or in a plane awaiting take off. You glance over at your neighbour’s phone screen – innocently, of course. But instead of a glowing feed of TikTok videos or the draft of an e-mail, you are met with a seemingly inert black screen, although this person’s thumbs are swiftly tapping it.

It is like a slap on the wrist, a “Keep out” sign, a trap set for nosy people who cannot resist snooping on other people’s phones. It is a privacy screen, an accessory for phones and laptops designed to significantly darken or totally obscure their surfaces to wandering eyes.

Lately, the screen protectors have become a common sight in densely populated public areas. They have become particularly popular among people with sensitive professions, such as doctors and therapists, who must be cautious about their patients’ personal information when working outside their offices.

But at a time when it has become normal to assume a level of surveillance in public places – not just by security cameras, but by our fellow travellers in this mortal coil who may turn us into internet content – the screens have become more appealing to the average person too.

“I don’t like people looking at my stuff,” said Ms Shanaisa O’Neal, who was scrolling her phone, its screen visible only to her, as she rode the F train in Manhattan with her daughter on a recent afternoon.

Ms O’Neal bought a screen protector after catching an older man “naturally” looking over at her phone one day while riding the subway. As someone who occasionally checks her bank account in public and keeps photos of her home and her children on her phone, she felt the privacy shield was necessary.

Asked if she ever looked at the screen of a person sitting next to her, she said her eyes “may” drift in that direction, but that she has never looked at someone else’s phone intentionally. She paused before continuing: “Okay, maybe I have before.”

Even more than personal details such as banking information, what some people say they are most trying to prevent is someone seeing – and judging – the mundane ways they pass time scrolling.

“I waste so much time, especially on the phone, and the last thing I need is someone saying, ‘Oh, he’s on Instagram,’” said Mr Guy Knoll, a 21-year-old comedian living in Gramercy Park.

He admitted that one of his favourite things to do for his own amusement is judge people on the subway for watching weird things in public, such as “someone tweezing out a bullet” or “some dumb video of an animal”.

Poking fun at himself, Mr Knoll admitted that any judgment of his Instagram habits, for instance, would probably be warranted “because it is a degenerate activity to just be on social media all day”, as he put it.

Some of that online content, typically tailored to suit a person’s tastes via “the algorithm” – the ominous shorthand for the calculations websites use to anticipate and predict people’s preferences – can seem more revealing than a passport when it is exposed to strangers.

According to behavioural scientist Leslie John, a professor at the Harvard Business School who studies privacy decision-making, what people choose to post is one facet of themselves that they want other people to see.

But what is regurgitated back to people by social media algorithms, which are becoming “scarily good” at understanding users, may reveal what they actually care about.

“That is much more revealing to someone because we’re not censoring it,” she said. “It feels more personal because it is more personal.”

How do those algorithms know you so well? It is because most phone users are forking over tons of data and personal information to tech companies every time they download an application or search online. Yet, somehow the stuff you want to keep the person sitting next to you from seeing – your messages or the algorithm-driven content that ends up on your feeds – has become a locus of some people’s privacy concerns. Is it performative? A grasp for a comforting, yet false, sense of control? Both?

Psychologists refer to this mismatch, in which the value people place on privacy seems to be contradicted by their behaviour, as the privacy paradox.

Dr Dennis Stolle, senior director of American Psychology Association’s office of applied psychology, said the privacy screen was an example of people exerting their value for privacy in a situation where they know they can immediately and tangibly control the space around them.

“You can put that privacy screen over your laptop or phone and feel a sense of accomplishment,” he said. “Even though, in the big picture, that may be the least of your worries, it still is somehow psychologically satisfying to do something to protect the value that you hold of the importance of privacy rather than doing nothing at all.”

As a creative arts therapist, Ms Karen Codd was “primed” to be protective of the communications she has as part of her job as well as in her personal life.

At the same time, she noted that there was some cognitive dissonance with her life online.

“For example, I just described the importance of confidentiality, but I’m also a therapist who has a dating profile,” said Ms Codd, 44. “If I want to be a person connected to culture or able to socialise or meet new people, I have to be vulnerable in some respects.”

On a subway platform at the West Fourth Street station in Greenwich Village, Mr Varun Punater, 23, pushed his index finger across his darkened smartphone filter that was peeling and cracked from long-time use. The main reason he started using a privacy protector nearly four years ago was to jokingly spite a friend who had bought one first.

“It’s kind of stupid, but I couldn’t see what he’s up to and I’m a snoopy person, so then I was like, you know what, I’m going to get one too,” he said.

He liked the sense of security it gave him, especially while on public transit, but he acknowledged that it does not compare with how his personal data is being used online without his permission.

“It’s always like a give-and-take with privacy,” said Mr Punater, a computer science major at the University of Southern California. “What you choose to give up right now is out of your hands.” NYTIMES