I recently read the book “I See You” by Claire Mackintosh. It’s a page-turning psychological thriller, but the book also raises interesting questions about how our personal privacy is at risk — in myriad ways.

Zoe is an average working mother who takes the “Tube” from her South London home into the central city every day. One day she picks up a free newspaper and is shocked to see her picture featured in an ad for an online dating service called “Find the One.” The photo could have been taken only by a stranger — perhaps while Zoe was traveling to work. She’s not the only one targeted. …

It’s easy enough to pretend to be taking a selfie when, in fact, you’re snapping a pic of somebody else. And in a crowded subway train, who’s even going to notice? Everyone is dozing off, staring at their own phones or suspiciously watching people who appear to be drunk or stoned.

As a school librarian, I was initially in favor of allowing high school students to use their smartphones in the library. Not to talk on, but to listen to music through earbuds, use the calculator or search for information they needed for assignments. It was my understanding that some students even did their projects right on their phones.

But as social media became more pervasive, I realized that students could — and did — take pictures of unwitting subjects and post them online. When Snapchat came on the scene, this practice escalated. It was time to ban cellphones in the library.

We lend them calculators, and have 16 computers available for research, not to mention a library full of books. I also think it’s a good life lesson to realize we can survive without our cellphones for 90 minutes.

I have not had my likeness hijacked yet — or, should I say, that I know of. I am unphotogenic, so I am confident I will never pop up in a dating ad a la “I See You.” Still, the thought is unnerving.

I’m more bemused than worried about other privacy breaches. It’s annoying when I search for something via Google, and then related material appears in my Facebook feed. For example, I had been reading the mystery novels written by Louise Penney, which are set in the Eastern Townships of Quebec. I researched the Eastern Townships. For weeks now, the Eastern Townships tourist authority has been sending me alluring links, in hopes of getting me up there.

On the one hand, I know that any ads that pop up are the result of an algorithm that uses data about sites I visit. Do I care about this? I’m not sure. This information might even be useful to me. The Eastern Townships aren’t far away. Perhaps I’d like to visit once the weather warms up. The last time I went to Quebec in April it snowed. July might be safe.

It is true, too, that sometimes when Amazon and Netflix send me suggestions for my next literary and cinematic experiences, they sound like something I might like.

Other times they are way, way off base.

I guess my bottom line is that a photo of me taken without my permission and posted for the world to see is a definite violation of my privacy. But does anyone, including me, really care that I checked out Saint-Denis-de-Brompton and East Angus, Quebec? Or that I regularly order 10-pound bags of Hershey Miniatures from Amazon Pantry? Or that the last Netflix DVD I watched was “Jackie”?

Perhaps we should, but I don’t think we do. Our “Big Brother” is not the constant, invasive telescreen that orders Winston Smith to do a better job of touching his toes and watches his every move in George Orwell’s “1984.”

We can turn off our phones, TVs and computers. An algorithm is not a person. Our candy consumption is of no concern to anyone. Who cares if I have an interest in Canada? Or that I have downloaded “1984” onto my iPad and re-read it every year? Sometimes I highlight lines by mistake. Are there Thought Police keeping track of that?

Of course not. Who cares what I think, what I do, where I go?

And yet, I recently saw an 8-year-old semi-creeping down the hallway of his elementary school, looking around suspiciously. “They’ve put cameras in,” he said. “Look.”

Electricians had been working in the school that day; to put in lights, I think.

Though the boy was joking, I looked.

Liz Soares welcomes e-mail at lsoareswriter@gmail.com.