It was a recurring joke that Ronald Reagan strategically deployed during his presidential campaigns: The most frightening person you could find at your front door was someone who said, “I’m from the government, and I’m here to help you.” A modern analog to this might be someone telling you that “Michael Lewis is at the door, and he wants to see how you use the Internet.”

It isn’t that anyone familiar with his work would worry that he would do a hatchet job on you; he comes across, for the most part, as both open and fair. But Lewis’s latest book, Next: The Future Just Happened, conveys the distinct impression that you are better off having his keen, if sometimes jaundiced, eye focused elsewhere. He’s the sort of person you want in your living room, telling you about someone else; you don’t want him telling someone else about your living room. And you really don’t want him describing you.

Greg Lebed, for example – the father of Jonathan Lebed, a teenager who made some $800,000 trading stocks on the Internet, and ran afoul of the SEC – is introduced this way: “Black hair sprouted in many directions from the top of his head and joined together deep in the middle of his back. The ‘Ape Drape.’ The curl of his lip seemed designed to shout abuse from a bleacher seat. Dress him as an Eskimo and drop him into the Arctic Circle and he’d remain, unmistakably, Essex County. Anyway, that was the first impression he made, of a man perfectly untamed, a creature at home only in the New Jersey wild.”

The story of the younger Lebed and that of Marcus Arnold may be familiar, along with other bits and pieces of the book, to readers of the New York Times Sunday Magazine to which Lewis is a regular contributing writer. Arnold, another precocious young teen, and his family live in a development on the edge of a California desert into which recreational parachutists surreally glide, visible through the Arnold family’s windows, as a backdrop for conversations. Arnold is noteworthy for managing to gain an on-line reputation for dispensing legal expertise beyond his years and education.

Material from the book can also be found in the BBC documentary series with which it was co-produced (the title of which shed the word “Next”) and on the BBC’s companion website. In the U.S., A&E picked up the documentary series, reinserting the “Next.”

Together, these two teenagers and their stories take up almost half of the book. Lewis sees one of the primary impacts of the Internet – or, at any rate, of the world wide web – as a disruption of traditional social roles and positions, often inverting the positions of parents and children, insiders and outsiders, siphoning power from traditional centers and transferring it to the edges of society.

One classic example he gives of the leading edge of this trend is the way that grandparents and parents became dependent on children to do things like program their VCRs. By the time we get to Jonathan Lebed – who had discovered, at age 14, the power of buying low, launching e-mail campaigns before going to school and selling high when school let out in the afternoon – we have the spectacle of teachers interrupting students as they take tests to pull them out into the hallways and pump them for stock tips.

There is something both unsettling, and indeed a bit freakish, about a number of the families in which these young savants live. Lewis paints a compelling picture of incomprehension and impotence on the part of the parents, alloyed by the occasional note of sheepish pride. One variant on Lewis’s central thesis is the idea that these students, using the mask of the Internet, are escaping from their usually unsatisfactory adolescent experiences not via the more typical and time-tested device of nostalgia – which would require them to wait it out and then re-write things in retrospect – but through an option not available to previous generations: They project themselves into a new virtual present, in which they really can be lawyers (well. . . almost) and stockbrokers (no question at all) while still in high school.

The book is broken into four parts. The first, “The Financial Revolt,” which is almost wholly Lebed’s story, is the most coherent. The second, “Pyramids and Pancakes,” which deals with the manner in which the Internet is facilitating a flattening out of hierarchical structures, begins with a section on Marcus Arnold and then moves on, fragmenting a bit, though remaining compelling and interesting. The last two sections, “The Revolt of the Masses” and “The Unabomber Had a Point,” while also dense with interesting characters and witty descriptions, could have used a good deal more work on structuring the internal transitions. The documentary series is delivered in four installments; it may be that there are cleaner and clearer visual and auditory segue cues in the video version. For the book, things might have been divided in slightly different fashion.

The last two sections are more complicated in part because they raise thorny questions that are, in many ways unanswerable. The web is facilitating an increasingly personalized consumer culture, but this is being accomplished in part via a loss of privacy; if you want more personalized products, you have to let yourself be more comprehensively known. The cost of cheaper consumer goods is the broadcasting and ultimate sale of your personal data – where you’ve been and when, what you’ve bought and how often.

Is this good or bad? For the most part Lewis seems to think that it’s good. The notes of ambivalence which filter through, as well, however, are welcome, and they are consistent with a general tone of exploration. The most problematic aspect of the book may be that the bursting of the high tech bubble has made any predictions about the inevitability of various changes somewhat suspect – an irony that cannot have escaped as keen an observer as Lewis.