Recently, a friend sent me an email with the subject, “Twitter targeted me with this ad.” The body of his email said, simply, “I hate technology,” then showed a pasted screenshot of a promoted tweet from a Muslim dating service. My friend has an ethnic name, but he doesn’t tweet about religion. Still, some data-driven algorithm, using overly generalized or just plain incorrect information about my friend, decided that the dating service tweet was reaching its target audience by targeting him.

If there is indeed false data about my friend archived online, it may be impossible to access and correct it, Julia Angwin discovers in her informative, conversational new book, Dragnet Nation: A Quest for Privacy, Security, and Freedom in a World of Relentless Surveillance (Times Books, February 25). Angwin, a former Wall Street Journal and current ProPublica senior reporter, studied more than 200 commercial data brokers, of which she was sure there were more. These Web-based companies collect personal information to sell or to advertise against. And only about 15 percent of them let her see her own data—sometimes only after entering even more information to gain access. After contacting 23 sites, she received her data from 13 of them. The rest of the brokers were inaccessible to the people whose information they stored and sold.

The mission to inventory her data from commercial collectors was just one futile quest of many in Dragnet Nation, in which Angwin, whose previous book was about the rise of MySpace, ushers readers through her efforts to opt out of the pervasive tracking and surveillance that companies and the federal government engage in to quantify every last bit of our lives. “I would attempt to avoid being monitored during everyday activities such as reading and shopping,” she writes.

I would obscure my location—at home and while out and about. I would seal my emails and texts with the digital equivalent of hot wax . . . I would try to find a way to protect my kids from building a digital trail that would haunt them later in their lives.

Angwin has been reporting on privacy and technology for several years, and she describes her evassive efforts as an attempt to identify alternatives to a society—our society—where people’s data can be scooped up en masse and then used against them. Within the industry, journalists are already paying attention to the potential dangers of data collection, since the Obama administration has made a habit of treating intelligence reporting as a crime. But Angwin builds a compelling case that, even for the broader public, the post-9/11 acceptance of foregoing privacy for safety was a bad and unnecessary trade—that “some research suggests that collecting vast amounts of data simply can’t predict rare events like terrorism,” but it will turn common connections into red flags. Just using encrypted online tools can mark a person as someone the government should scrutinize.

To evade the digital dragnets, Angwin does a host of research on the best apps and strategies for keeping all her information encrypted or untrackable. She finds that most of these services have significant drawbacks. She quits using Google search, which, she notes, stores users’ entire search history, mining it to display customized Gmail ads. But when using DuckDuckGo, a search engine with a zero-retention policy, Angwin couldn’t depend on her Google databank to help guide her searches; she had to learn a new search language. Encryption email, browser, and chat programs are slow and unwieldy, and they’re mostly run as techie passion projects prone to closing from lack of funding or, in the case of Lavabit, to prevent the government from subpoenaing Edward Snowden’s emails. Using a fake name online made her uncomfortable. Even the simplest, cheapest privacy fix Angwin used—preventing her cellphone from being tracked by wrapping it in aluminum foil—was a tall order to maintain, since the foil quickly crumbled. And with two young children, being unreachable throughout the day was untenable.

Angwin takes short detours from her memoir of sorts to interview various encryption acolytes and program creators and provide an overview history of surveillance, to drill home the stunning amounts of data collected on Americans in the course of a normal day. The third-person reporting adds voices and perspectives to her tale that keep Dragnet Nation from becoming a dry how-to.

Her quest to remove herself from the digital bullseye meets with mixed success, at best: Angwin finds it impossible to fully disconnect from data dragnets. But her travails educate her (and her readers) about all the ways privacy-minded developers are working to develop anti-surveillance tools, and this forms a helpful guide for readers seeking non-jargony information on minimizing their digital footprints.

Kira Goldenberg is an associate editor at CJR. Follow her on Twitter at @kiragoldenberg.