"Dirty Harry had his forty-four. Sherlock Holmes had his brain.
Evan Guttman had his computer, the Web and a couple thousand people he never met. That was enough.
Three weeks ago, Mr. Guttman went on an epic quest to retrieve a friend's lost cellphone, a quest that has now ended with the arrest of a 16-year-old on charges of possessing the missing gadget, a Sidekick model that retails for as much as $350. But before the teenager was arrested, she was humiliated by Mr. Guttman in front of untold thousands of people on the Web, an updated version of the elaborate public shamings common in centuries past.
The saga began when Mr. Guttman's best friend Ivanna left her cellphone in a taxicab, like thousands of others before her. After Ivanna got a new Sidekick, she logged on to her account - and was confronted by pictures of an unfamiliar young woman and her family, along with the young woman's America Online screen name.
The 16-year-old, Sasha Gomez, of Corona, Queens, had been using the Sidekick to take pictures and send instant messages. She apparently did not know that the company that provided the phone's service, T-Mobile, automatically backs up such information on its remote servers. So when Ivanna got back on, there was Sasha.
Using instant messages, Mr. Guttman tracked down Sasha and asked her to return it. "Basically, she told me to get lost," Mr. Guttman recalled. "That was it."
So he set up a no-frills Web page with a brief account of what happened, and posted the pictures of the girl and her family. Within hours of putting up the Web page, Mr. Guttman was fielding hundreds of e-mail messages from those nursing their own bitter memories of a lost cellphone, a Blackberry or a digital camera that went unreturned.
There were links to the page on Digg and Gizmodo, two popular tech-oriented blogs, which helped drive more and more traffic. Eventually, hundreds of other Web sites posted links to his page. The hundreds of e-mail messages became thousands from as far away as Africa and Asia. Mr. Guttman tried to answer them all, and barely slept. "A lot of people have been saying, 'I lost my phone, I wish I did this,'." he said.
Some readers also began visiting Sasha's MySpace page and bombarding her and her friends with e-mail messages. Others found her street address in Corona and drove by her family's apartment building, taking videos or shouting out "thief" in front of her neighbors.
Meanwhile, lawyers and police officers sent Mr. Guttman e-mail messages instructing him on the finer points of property law and advice on how to navigate the police bureaucracy. Some readers took to Internet forums, where they exchanged their own stories of lost phones and recalled the time last year when Paris Hilton's Sidekick was hacked, allowing millions of people to view her pictures and personal address book.
The site continued to draw e-mail messages and rack up visitors. When Mr. Guttman's Web server crashed from the traffic, several people offered free server space. A reader in Orlando, Fla., recorded a song about the missing Sidekick and posted it on a MySpace page. (Sample lyrics: "Materialistic-kleptomaniac/please just give her her Sidekick back.") Another, Mr. Guttman said, invited him to a party at the Playboy mansion in Los Angeles. Still others located Mr. Guttman's personal site, which is not directly linked to the Sidekick page, and found photographs that he has taken of swimsuit models, some of them seminude. They accused him of an intricate scheme to sell pornography, which he laughed off.
Mr. Guttman also kept exchanging e-mail messages with Sasha and, eventually, her family. Then he heard from her older brother, Luis Pena, who said he was a military policeman and warned Mr. Guttman to leave his sister alone.
Mr. Guttman posted the exchange.
Within days, he was contacted by dozens of active and retired soldiers. One said he had gone through basic training with Mr. Pena; several others told Mr. Guttman that making such a threat was a violation of military policy and promised to report Mr. Pena to his superior officers.
Mr. Guttman posted it all.
"I don't want people to be punished," he said last week. "I just want them to give the Sidekick back."
The girl's family was not pleased by the attention, especially the random visitors to their street. Though Sasha and Mr. Pena did not respond to several instant messages and e-mail messages seeking comment, their mother, Ivelisse Gomez, confirmed that her son was serving in the Army and had got into trouble with his superior officers after some of the visitors to Mr. Guttman's Web page called in to complain. She also said that Mr. Guttman's Web site amounted to harassment and said the family might sue him.
"They told him to come pick it up," said Ms. Gomez, speaking in the apartment of her building's superintendent. She said she bought the phone for $50 on a subway platform in Queens and gave it to her daughter. "We said he could have it if he gave the money we paid for it," she added.
Mr. Guttman, however, said that the offer to retrieve the phone was accompanied by a threat of physical injury. So after posting a warning that Sasha had one last chance to return the phone, he accompanied its actual owner, his friend Ivanna, to a Manhattan police station. Ivanna asked that her last name be kept private, as she was about to be married, and, she said, "I don't want to be famous for having lost my Sidekick."
"I was worried, because I had all this information on the phone - all these numbers and e-mails, personal and work," she continued. "So I called Evan, because he's really good with computers."
People are not nice," she added, referring to Sasha. "Why?"
Last Thursday, the saga of the lost Sidekick began meandering toward a conclusion. The police arrested Sasha and charged her with possession of stolen property in the fifth degree, a misdemeanor. (The police have possession of the Sidekick and plan to return it to Ivanna.) Sasha was released, but was not available to speak to this reporter. Her mother offered a parting comment.
"I never in my life thought a phone was gonna cause me so many problems," Ms. Gomez said.
