One day in May 2005, a 16-year-old hacker named "SoBe" opened his front door to find a swarm of FBI agents descending on his family"s three-story house in Boca Raton, Florida. With an arm and leg in casts from a recent motorcycle accident, one agent grabbed his good arm while others seized thousands of dollars worth of computers, video game consoles and other electronics. His parents looked on.

At that moment, some 2,700 miles away, in the Los Angeles suburb of Downey, California, the FBI was serving a separate search warrant on Jeanson James Ancheta, SoBe"s 20-year-old employer and hacking mentor. It was the second time in six months Ancheta had been raided by the FBI -- a clear sign, had they bothered to notice, that their year-long botnet spree was unravelling.

But instead of abandoning the venture after the first raid, or at least laying low for a while, SoBe and Ancheta, according to court documents, continued hijacking hundreds of thousands of PCs that they would then corral into massive networks and infect with adware. So great was SoBe"s sense of impunity he continued the scheme even after Ancheta was arrested a few months later and charged with 17 felonies related to the hijacking of almost 400,000 PCs, some of them belonging to the US Department of Defense.

"That"s why I love this age, its all computers heh," SoBe wrote in early December 2005, a month after Ancheta"s arrest, during an online chat. "All these companys have websites, etc. Its just funny going somewhere like Target or Sprint then coming home and rooting there servers out of boredom. Makes some people feel like they can do anything." (Editor"s note: Misspellings and grammatical errors from the chat have been preserved.)

SoBe"s adrenalin-fueled days of fast money were slowly coming to an end.

His downfall started shortly after he and Ancheta launched their botnet venture, when some clumsy mistakes attracted the attention of federal investigators. It continued as their homes were raided, and shortly after that, when the federal law enforcement seized more than $38,000 earmarked as SoBe"s cut of the botnet profits.

Then in May 2006, SoBe was shocked when he learned Ancheta received 57 months in prison after pleading guilty to four counts of fraud related to the scheme.

His undoing was completed in February, seven months after SoBe turned 18, when he pleaded guilty to two counts of juvenile delinquency related to his use of botnets.

SoBe -- who also went under the names SoBe Owns, PwnZ0r, SerlissMc and vapidz -- admitted to infecting computers belonging to the Defense Information Security Agency and Sandia National Laboratories. He was sentenced on Thursday in a closed-door hearing. Although the actual sentence is confidential because SoBe had been a juvenile at time of the crimes, his plea agreement contemplated a prison term of 12 to 18 months.

(Editor"s note: Because Sobe was a juvenile when he committed the acts for which he was prosecuted, he was not identified by law enforcement officials and will only be identified by his online pseudonym, Sobe, in this article.)

In November, 2005, just a few days after Ancheta was indicted, SoBe began an Internet correspondence with this reporter that continued until a few weeks before he pleaded guilty. The result was more than 80 pages of single-spaced transcripts that provided a sometimes-candid, behind-the-scenes account of his botnet caper and the investigation that ultimately shut it down.

The conversations revealed a youth of above-average intelligence who nonetheless quit school after the eighth grade. With an abundance of time on his hands and little adult supervision, he thrived on the excitement of a life dominated by World of Warcraft, fast motorcycles and computer hacking. The Register is not identifying him because his crimes took place while he was a minor.

The son of a father who worked as a landscaper and a mother who taught middle school, SoBe came of age in Boca Raton, an affluent town about an hour"s drive North of Miami made up mostly of older retirees. After quitting school, he spent much of his days coding in C++ and frequenting IRC channels related to hacking. It was in a now-defunct channel called #bottalk that he met Ancheta, who typically went under the moniker Resilient.

"He stood out from all the other people basically because he didnt bullsh*t people," SoBe recalled. "Most people you meet in the bot scene will claim they have xxxxx amount of bots but they dont and they lie about everything."

Unlike the others, Resilient had proof that he had sizable botnets under his control.

"You can"t really lie about that when you take screenshots proving you have well over 70k," SoBe said. "It"s hard to fake hundreds of exploit messages with unique IP addresses and a picture of him in a channel with 60,000 users."

SoBe was also drawn to Ancheta"s social flair as demonstrated, among other things, by a MySpace profile that was packed with photos of his souped-up BMW and a passel of photogenic friends. "He isnt like your average computer nerd," SoBe explained. "He actually goes outside, has fun, partys."

Not all their hacking was business related. The two were part of a posse that defaced websites by compromising, or "rooting," vulnerable servers. They took great pride in their mischievous exploits, which they documented with graffiti they left behind.

But by and large, SoBe and Ancheta"s relationship was about making money. When they first met, Ancheta"s business model was in the midst of a major overhaul. He had been renting out his bots in a channel titled #botz4sale, but despite brisk demand, he hadn"t been able to bring in the kind of money he hoped for. (According to fees tracked by prosecutors, it was less than $3,000, although the true fee was probably higher.)

Ancheta recruited SoBe to help him launch a new scheme installing adware on Ancheta"s fleet of compromised machines and using them to generate pay-for-click affiliate fees from companies such as Gamma Entertainment, which ran a program called GammaCash; and CDT, which offered a program called LOUDcash. The new revenue model was an instant success.

"It"s easy like slicing cheese," Ancheta typed, to which SoBe responded: "I just hope this [LOUDcash] stuff lasts a while so I don"t have to get a job right away." In about a year, investigators tracked more than $58,000 in revenue from the scheme.

They felt unstoppable, SoBe said. Even after Ancheta"s home was raided, in December 2004, and FBI agents confiscated his computer, "he was back online within a day" and the two continued their botnet activities. He felt the same invulnerability after Ancheta was locked up.

"It doesn"t matter," SoBe insisted in the days immediately following his arrest. "James can get off, and go back to doing it and in under a month he will be making 3x what he made and be able to cover his tracks much better."

SoBe and Ancheta didn"t know it immediately following the raids, but thanks to several slip-ups, they had been under the watchful eye of FBI agents, who were quietly building a case against the two hackers. The first mistake was Ancheta"s brazen advertisements on #bots4sale, an act that moved him to the top of investigators" to-do list.

"Up to then, we hadn"t seen anything as blatant," FBI agent Ken McGuire said in a 2006 interview. "Anybody who"s blatant enough to advertise in internet message boards that you have botnets to sell is someone you want to clear off."

Not long afterwards, the pair came to the attention of investigators again, this time because of software bugs in rxbot, the package the two had appropriated and modified to build their bot empire. To keep the botnet growing, their zombie machines automatically looked for new machines on nearby networks to compromise. But as it turned out, their software was a little too aggressive.

"If it scanned its own subnet, its possible it would keep going and scan out of its subnet, potentially scanning a DoD network," SoBe explained. According to court documents, that"s exactly what happened. SoBe and Ancheta"s software ended up infiltrating machines belonging to the China Lake Navel Air Facility, the Defense Information Security Agency and Sandia National Labs.

"A lot of good evidence came from the military computers," McGuire said. "It was an excellent break in the case because it permitted us further analysis."

For their part, SoBe and Ancheta didn"t seem to grasp the severity of their error at the time. In August 2004, an associate warned Ancheta by IRC chat to be sure "to filter out sh*t though like .gov and .mils" when his malware sought new victims. But two months later, when SoBe told Ancheta "hey btw there are gov/mil on the box if you want to get rid of them," Ancheta responded "rofl," according to court documents.

Another big blunder was SoBe"s decision to lease a server using his real name and address. The pair used such boxes to host web servers and an IRC daemon that each of their bots reported to. By changing the topic in the IRC channels, they could cause the zombies to connect to other servers under their control and install any software they happened to host there. SoBe said he used his real identity "since i still dont approve of fraud."

SoBe was also convinced that investigators were able to infiltrate his botnet through a secret backdoor that had been built into their IRC daemon. He had gotten the program from Jonathan Hall, a hacker who in 2004 was charged -- but never convicted -- in a separate botnet investigation dubbed Operation Cyberslam.

The "server was in my name and [investigators] had a backdoor to gain oper status thx to some douchebags not telling us about it," SoBe complained bitterly.