The last time Kevin Mitnick surfed the Web . . . oops. Until last week, Mitnick, who is usually described as the world's most notorious hacker, and who was considered such a profound threat to American society when he was arrested, in 1995, that he wasn't even granted a bail hearing, had never actually surfed on the Internet. "You have to have some speed to surf,'' he said the other day. "When I went away, there was no such thing. I had rigged a special modem to keep me ahead of the feds during the years I was a fugitive. Most of the time I was connecting at 300 baud"-the average cable modem these days works five thousand times as fast. "Even then you couldn't surf on that.''

Mitnick, who broke into countless computers to steal trade secrets and proprietary software, was convicted of computer and wire fraud. The sentence was harsh, in part because he had vanished while on probation and taunted the F.B.I. for two years, but it was also intended as a deterrent to anyone who might try to emulate him. Last Tuesday, after five years in jail and three more on parole, during which he was prohibited from even connecting to the Internet, the self-described "Osama bin Mitnick of cyberspace" finally got back online. He celebrated his first day of computer freedom on an Internet tele- vision show called "TechTV." Because he had no idea how to navigate from one Web site to another (and wondered, by the way, what this thing called In- ternet Explorer was all about), he was assisted by two other hackers, Steve Wozniak, the co-founder of Apple Computers, and Emmanuel Goldstein, the publisher of the hacker quarterly 2600. Both were outspoken supporters of the "Free Kevin'' campaign, which became a sort of religion among computer geeks around the world.

"Don't be freaked out by advertising,'' Goldstein told Mitnick. "It's everywhere. So is pornography." Mitnick looked dazed by the concept of a pop-up ad.

"I had no idea even where to begin,'' Mitnick said later. "To finally have it all there, right in front of me, was a little bit daunting.'' So he did just what you might expect a cyberian version of Rip Van Winkle to do: he Googled himself. His maiden vanity search turned up more than forty-three thousand references to his name.

Mitnick's first stop was his girlfriend's Web log (labmistress.com). Her most recent entry consisted of a meditation on what she ought to buy him for a post-parole gift. (She settled on the new Blackberry 6710.) Among his other destinations were Amazon.com (to check the sales of his new book, "The Art of Deception"); the F.B.I. home page ("I just had to look"); a page owned by the actor Kevin Spacey (they are working on a film project together); and eBay (where there is often some Mitnick memorabilia for sale). Last week, one could actually buy his weapon-the Toshiba Satellite 4400SX laptop that was seized by the Secret Service during a raid on his apartment in Seattle in 1994. The laptop has been signed by both Mitnick and Wozniak, and the bidding started at eight thousand dollars. (Mitnick won't be needing it anymore. Wozniak presented him with a brand-new Apple Titanium Power Book, then said, "I'm pro-choice, so if you prefer a P.C. I'll buy you one.")

Mitnick now lives in Thousand Oaks, California, and, like many hackers who have gone straight, he has started a computer-security company, called Defensive Thinking. Like Frank Abagnale, the legendary grifter who is the subject of the film "Catch Me If You Can,'' Mitnick feels that his past wrongs qualify him perfectly to help businesses and government agencies protect themselves against people like him. "I know that it will be hard for people to trust me at first,'' he said. "But I am reformed. I broke the law, and I paid for it.''

In prison, Mitnick tried to keep current with computer culture, but the feds wouldn't have it. "They were ridiculous about it," he said. "My lawyer was not allowed even to show me data on a laptop, because the prosecutors said that if he brought a laptop to prison I could hack into the Pentagon and launch a nuclear strike, or hack into the Federal Bureau of Prisons and have myself released.''

Mitnick was bitter when he got out of prison, but his new freedoms seem to have mellowed him. "I plan to be online tonight,'' he said, excitedly. "I am going to get DSL and learn to use all the tools. I am going to check out online banking. I intend to use online everything."