With the reach of the Internet, an unprecedented worldwide appeal by Interpol brought hundreds of responses via e-mail to the French-based police agency.
And with the aid of traced cell phone calls, Thai police tracked the suspect to a house well off the usual tourist trail, in northeastern Thailand.
The high-tech police work resulted in the arrest Friday of Canadian schoolteacher Christopher Paul Neil, suspected of sexually abusing Asian boys, after a three-year global manhunt.
Neil, 32, was detained at a house that he had rented with a Thai transvestite friend in the rural province of Nakhon Ratchasima.
"I think he knew we were coming," said police Col. Paisal Luesomboon, who was on the five-member police team that made the arrest. "He knew that there was an arrest warrant issued and that his face was posted everywhere."
He said Neil acknowledged being the man they were seeking, but didn't comment on whether he was the person depicted in about 200 Internet photos having sex with a dozen different boys between the ages of 6 and 12.
Only 10 days earlier, Interpol had issued the appeal to identify the man whose face had been digitally obscured by swirling part of the original photos.
After German police computer experts were able to reverse the process, making the face recognizable, some photos of the man were publicly circulated, and hundreds of people responded with tips on his identity, leading to Neil's arrest.
"Let all international criminals and fugitives be put on notice that Interpol, its police partners in 186 member countries, the public and the Internet present new and powerful possibilities for hunting them down wherever they might try to hide," Interpol Secretary General Ronald K. Noble said in a statement.
Thai police made a big show of Neil's arrest, perhaps trying to counter their country's image as a center of the sex-tourism trade, reports CBS News correspondent Mark Phillips.
Taken to the Thai capital Bangkok, Neil - in handcuffs and with a blue shirt draped over his head - was led into national police headquarters. He made no comments to waiting reporters.
He remained silent and unsmiling when he was presented to journalists at a news conference, where the shirt was removed from his head but his eyes remained hidden behind a pair of sunglasses.
"He wants to exercise his rights not to speak until he gets legal advice," said Maj. Gen. Wongkot Maneerin, deputy national police chief.
Neil was charged Friday with detention of a child under 15 without parental consent, punishable by up to three years in prison; taking a child under 15 from his parents without consent, punishable by five to 20 years; and sexual abuse of a child under 15, punishable by up to 10 years.
He is supposed to be brought before a judge Saturday in order for police to keep him in custody pending further investigation.
The charges are based on the alleged abuse of a 9-year-old boy in Bangkok in 2003, but police say at least three other boys are believed to have had sex with him, and more charges may be filed.
Interpol called on his alleged victims to come forward.
"The investigation must now continue. All victims of this man must make themselves known," the head of Interpol's police services, Jean-Michel Louboutin, said at a news conference in Lyon, France.
He said five of nearly 400 e-mails received in response to its search put authorities on the suspect's trail.
It was the first time Interpol went to the public in search of a suspect, and "what functioned perfectly was the police-media-public link," Louboutin said.
On Thursday night, police traced a call made on a cell phone by a 25-year-old Thai man with whom Neil was previously known to be in touch, said Paisal, superintendent of the Tourist Police Division.
Police had earlier said the man had arranged some of Neil's alleged sexual liaisons with boys, but Paisal did not describe their relationship at Friday's news conference.
They found the Thai man, whom they described as a transvestite, in the northeastern province of Chaiyaphum. He told police he and Neil had rented a house together in neighboring Nakhon Ratchasima province, and he led the police there Friday morning.
Neil lived in Thailand from 2002 to early 2004, police said. Three Thai youths, aged 9, 13 and 14 at the time of their alleged abuse, contacted police Wednesday after seeing Neil's photograph on television, claiming he had paid them for oral sex in 2003, said police Maj. Gen. Wimol Powintara.
The boys said the suspect showed them pornographic images on his computer at his apartment in Bangkok, and paid them each $16 to $32, Wimol said.
Neil, of Maple Ridge, British Columbia, had taught at schools in Thailand, South Korea and Vietnam since 2000.
He suddenly left his most recent teaching job in South Korea last week on a one-way ticket for Thailand as investigators closed in. Cameras at the immigration counter captured his image as he arrived at Bangkok's international airport.
Before teaching in Asia, Neil had worked as a chaplain in Canada, counseling teens.
British Columbia Attorney General Wally Oppal said the Royal Canadian Mounted Police had Neil under investigation in Canada for complaints "involving young boys."
He did not elaborate. An RCMP spokeswoman, Constable Annie Linteau, said only that Neil was "a person of interest" but added that the force was asking Canadians with information on him to "call the child-exploitation tip line."
"The RCMP had received complaints here and so obviously we have an interest in what happens to him in Thailand," Oppal said.
He said Thai authorities have first right on prosecuting Neil but British Columbia will probably ask for his extradition, depending on what the province's criminal justice branch recommends. Canada has sex tourism laws allowing prosecution for crimes committed overseas.
Wongkot said Neil would "definitely" be prosecuted in Thailand. "He will have to go to Thai court first. After the case is over, then we can send him," he said.
Foreigners convicted of crimes in Thailand sometimes are declared undesirable aliens after their trials, and are expelled from the country.