Superhighway’s Rebels Without Causes : MASTERS OF DECEPTION: The Gang That Ruled Cyberspace, <i> By Michelle Slatalla and Josh Quittner (HarperCollins: $23; 256 pp.)</i>

For the thousands who have gotten up the nerve to dial up an on-ramp and venture onto the Information Highway, the arrest earlier this year of Kevin D. Mitnick, a fugitive hacker armed with a Toshiba laptop, a modem and an Oki cellular phone, flashed like the freeway sign in the movie “L.A. Story”: Caution: Infojacking Ahead .

Known as the “Condor,” Mitnick had eluded federal investigators since 1993, allegedly worming into computers, ferreting software secrets valued at thousands of dollars and revealing them on-line.

But high-tech hijinks are not limited to enigmatic loners; there are cyber-gangs too, as Michelle Slatalla and Joshua Quittner’s new true-life thriller shows.

“Masters of Deception” opens innocuously enough when a couple of New York teen-agers, Paul and Eli--using computers and software so rudimentary they’re laughable in this age of Windows and 1.2-gigabyte hard drives--hack into a phone company nerve center in Queens. Though it’s an irresistible technical challenge, the curious youths don’t get far.

Paul and Eli enlist the help of a shadowy master hacker known as Phiber Optik, blossom under Phiber’s tutelage and soon are hangin’ in cyberspace with some of the most respected hackers in the nation: The Legion of Doom.

These Texas-based legionnaires are aces at burrowing into the computer nerve centers of telephone companies, credit bureaus and rival bulletin board systems, where they manipulate, snoop and torment rival hackers and wanna-bes.

Using weapons ranging from chutzpah--gaining passwords by impersonating linemen--to clever programs designed to detect and slip through computer gateways, the hackers relentlessly probe and attack: posting Geraldo Rivera’s pages-long credit history, casting an upstart bulletin board operator into telephonic hell with a program that rings the hapless victim’s home number endlessly.

The payoff? Free long-distance chats, conference calls that go on for hours and involve dozens of people. But the hackers’ prime motivation remained “pure”: The rush lay in defeating the best security-measures system administrators could throw in their path.

There’s plenty of tagger-style rebellion here, complete with pixel taunts (“Happy Thanksgiving you turkeys,” and “Haha! You want to log in? Why? It’s empty!”) that greet users of WNET, the New York public broadcasting station, after the cyber-vandals breach WNET’s computer.

“Masters of Deception” would be a mere rehashing of juvenile electronic escapades had the authors, both Newsday reporters, not revealed the hackers’ human dimensions. For all their techno-talent, these young men are bedeviled by the classic issues of teen-age angst: acceptance, peer-pressure, self-control, ethics, friendship, direction, identity.

In other communities and times such struggles manifest themselves in fistfights, drag races or shootings. On the electronic frontier, as in real life, the relentless drive to prove something can result in disaster, as the hackers discover.

One night John, a bright, inner-city youth with a knack for voice impersonations bursts into a Legion of Doom “bridge”--a hacker-arranged conference call--with some friendly, affected jive: “Yo, dis is Dope Fiend . . .”

“Get that nigger off the line!” one of the Texas youths fires back. In the moment of stunned silence that follows, computerdom camaraderie crumbles. John (a.k.a. “Corrupt”) happens to be black.

“That word hit John like a billy club,” recount the authors. “Here he was, calling up probably some of the same guys he’s chatted with who knows how many times and the class clown decided to tease them a little. . . . He never figured that his joke would elicit such a response.”

In short order, the Bronx-Queens faction, who have taken to calling themselves the Masters of Deception, are engaged in cyber-firefights--spying, tapping phone lines, trading on-line insults and even planting “logic bombs,” programs designed to go off at a predetermined time and wipe out entire computer systems.

When AT&T; is paralyzed by a mysterious catastrophe that shuts down half of the nation’s long-distance calls, each soldier is left wondering if the baud-squad war has gone too far. Will the Justice Department be knocking down their doors, arrest warrants in hand? Can a jail cell--and you can bet it has no phone jack--be far away?

Written in a staccato style befitting its subject, “Masters of Deception” is a compelling look at our increasingly wired society . . . and fair warning to navigate warily on the InfoBahn.