The Circle by Dave Eggers Knopf/McSweeney’s, 491 pp., $27.95

The Circle is Dave Eggers’s tenth work of fiction, and a fascinating item it is.

Eggers’s first major book was the much-acclaimed semifictional memoir A Heartbreaking Work of Staggering Genius (2000), which recounts the struggles of Eggers to raise his younger brother after the death of their parents. By that time he was already active in the underground worlds of comic strip writing, small-magazine founding, and columnizing in the then-embryonic realm of online magazines. He has continued along a multibranched road that has included the founding of McSweeney’s magazine and publishing house, and an associated monthly, The Believer; of 826 Valencia, a youth literacy charity; and of ScholarMatch, connecting non-rich college-age kids in the San Francisco Bay Area with donors.

Then there’s the writing: the screenplays, the journalism, and, of course, the books. These include two unflinching looks at man’s inhumanity to man, in Africa and America respectively—What Is the What and Zeitoun—and the novel A Hologram for the King, which glances at the decline of America’s international clout through the eyes of a sad salesman. Eggers appears to run on pure adrenaline, and has as many ideas pouring out of him as the entrepreneurs pitching their inventions in The Circle.

The outpouring of ideas is central to The Circle, as it is in part a novel of ideas. What sort of ideas? Ideas about the social construction and deconstruction of privacy, and about the increasing corporate ownership of privacy, and about the effects such ownership may have on the nature of Western democracy. Dissemination of information is power, as the old yellow-journalism newspaper proprietors knew so well. What is withheld can be as potent as what is disclosed, and who can lie publicly and get away with it is determined by gatekeepers: thus, in the Internet age, code-owners have the keys to the kingdom.

Marshall McLuhan was among the first to probe the effects of different kinds of media on our collective consciousness with The Gutenberg Galaxy (1962) and Understanding Media (1964). Even then, before interactive technologies, he pointed out that “the global village” could be an unpleasant and claustrophobic place. As far back as 1835, Toqueville’s Democracy in America predicted the tyranny of public opinion, a tyranny that can be amplified immeasurably via the Internet.

The concerns that underlie The Circle are therefore of long standing, but have been much discussed recently, not only in newspapers and magazines both online and off, but in books. Misha Glenny has written eloquently about cybertheft and cybercrime in McMafia and DarkMarket, and, in Black Code, Ronald Deibert has detailed various cyberthreats to democracy and privacy. In The Boy Kings, a 2012 memoir that chronicles the early days of Facebook, Katherine Losse questioned the desirability of making personal information public.

This, then, is the “real” world to which Eggers holds up the…