When searching for an adjective to describe our comprehensively surveilled networked world – the one bookmarked by the NSA at one end and by Google, Facebook, Yahoo and co at the other – "Orwellian" is the word that people generally reach for.

But "Kafkaesque" seems more appropriate. The term is conventionally defined as "having a nightmarishly complex, bizarre, or illogical quality", but Frederick Karl, Franz Kafka's most assiduous biographer, regarded that as missing the point. "What's Kafkaesque," he once told the New York Times, "is when you enter a surreal world in which all your control patterns, all your plans, the whole way in which you have configured your own behaviour, begins to fall to pieces, when you find yourself against a force that does not lend itself to the way you perceive the world."

A vivid description of this was provided recently by Janet Vertesi, a sociologist at Princeton University. She gave a talk at a conference describing her experience of trying to keep her pregnancy secret from marketers. Her report is particularly pertinent because pregnant women are regarded by online advertisers as one of the most valuable entities on the net. You and I are worth, on average, only 10 cents each. But a pregnant woman is valued at $1.50 because she is about to embark on a series of purchasing decisions stretching well into her child's lifetime.

Professor Vertesi's story is about big data, but from the bottom up. It's a gripping personal account of what it takes to avoid being collected, tracked and entered into databases.

First – and most obviously – she determined that there would be absolutely no mention of her new state on social media. She phoned or wrote individually to friends and family members to give them the good news, and asked them not to mention it on Facebook. But an uncle in Australia sent her a congratulatory message via Facebook. "I then did," she said, "what any rational person would do. I deleted the thread of all our conversations and unfriended him." He replied plaintively: "But I didn't put it on your wall", apparently unaware that chats and other messages aren't private in the sense that he assumed.

In preparing for the birth of her child, Vertesi was nothing if not thorough. Instead of using a web-browser in the normal way – ie leaving a trail of cookies and other digital tracks, she used the online service Tor to visit babycenter.com anonymously. She shopped offline whenever she could and paid in cash. On the occasions when she had to use Amazon, she set up a new Amazon account linked to an email address on a personal server, had all packages delivered to a local locker and made sure only to pay with Amazon gift cards that had been purchased with cash.

The really significant moment came when she came to buy a big-ticket item – an expensive stroller (aka pushchair) that was the urbanite's equivalent of an SUV. Her husband tried to buy $500 of Amazon gift vouchers with cash, only to discover that this triggered a warning: retailers have to report people buying large numbers of gift vouchers with cash because, well, you know, they're obviously money launderers.

At this point, some sobering thoughts begin to surface. The first is Melvin Kranzberg's observation that "technology is neither good nor bad; nor is it neutral". Our technologies have values built into them, which is why Vertesi in her talk cites someone's observation that "the iPod is a tool to make us moral" (because it encourages people to buy music rather than download it illicitly) and philosophers argue about whether surveillance encourages moral – ie socially approved – behaviour (think speed cameras).

Even more sobering, though, are the implications of Professor Vertesi's decision to use Tor as a way of ensuring the anonymity of her web-browsing activities. She had a perfectly reasonable reason for doing this – to ensure that, as a mother-to-be, she was not tracked and targeted by online marketers.

But we know from the Snowden disclosures and other sources that Tor users are automatically regarded with suspicion by the NSA et al on the grounds that people who do not wish to leave a digital trail are obviously up to no good. The same goes for people who encrypt their emails.

This is why the industry response to protests about tracking is so inadequate. The market will fix the problem, the companies say, because if people don't like being tracked then they can opt not to be. But the Vertesi experiment shows that if you take measures to avoid being tracked, then you increase the probability that you will be. Which is truly Kafkaesque.