Canadian John Wrenshall stands accused of bringing American child predators to Thailand to have sex with children, filming their crimes and then distributing the images over the Internet.

But late last month, the 62-year-old was extradited from Britain to the United States to face trial, in an operation led by U.S. federal immigration police.

The U.S. Immigration and Customs Enforcement agency is best known for its role securing the United States' physical borders against drug and human smugglers and traffickers.

But it is now playing a role policing the nation's "virtual frontier" against a surge in child pornography, sex tourism and trafficking in minors carried out over the Internet.

"Bad things, harmful things, dangerous things, criminal things are crossing unseen electronically," said special agent Don Daufenbach, speaking over the hum of computer servers at ICE Cyber Crimes Center, or "C3," a few miles outside Washington D.C.

"Our job is to stop bad things coming into the country."

Specialized agents, combining police, intelligence and computer forensic skills, work with counterparts from police forces across the United States and around the world.

"We don't really care where the bad guy is, we don't really care who grabs them first, the main objective here is to protect the child," said Daufenbach whose team's efforts have led to the arrest of over 11,600 people worldwide since 2003.


More than 1.5 billion people currently go online around the world, a figure that is expected to reach 2.2 billion by 2013, according to a recent study by Forrester Research.

Investigators and child protection experts say child exploitation is exploding online as broadband access grows and the cost of laptops, digital cameras and videos fall.

The National Center for Missing & Exploited Children has reviewed some 25 million child pornography videos and images circulating online in the past six years alone.

"Suddenly the pedophile ... discovers that there are thousands like him around the world, with whom he can network and connect," said NCMEC president Ernie Allen.

"There is clear evidence that these people are ... sexually abusing children, photographing or videoing it ... and distributing it to like-minded individuals."

Aside from so called "peer-to-peer" sharing among predators, investigators say a growing number of tech-savvy criminal organizations are also piling into the activity.

They increasingly sell child pornography through web sites that can be put up and taken down in hours, banking the profits through online card processing centers.

"What we're now finding are criminal enterprises harnessing technology and using the Internet to make it a business. It's a global epidemic," said Jae Alexander Khu, section chief at C3, which also probes money laundering and intellectual property theft.


In May, President Barack Obama announced he would name a coordinator to lead the fight against cybercrime threatening the networks that underpin the U.S. government and economy.

But Melissa Hathaway, who led a 60-day White House review of cyber policies, resigned this month and withdrew her application because of delays in filling the post.

As the government grapples with its cybercrime strategy, ICE investigators say online predators are using ever-greater cunning to hide their identities.

Some use "cloaking devices" -- technology that masks a computer's network location or IP address.

They are also storing hundreds of thousands of images and videos of abuse on easy-to-hide "thumb drives" or even stashing files online.

"Online storage is horrible. Let's say, I go through someone's computer and I do not see that he's got an account somewhere for online storage, I may never find that," says Peter Buchan, a computer forensic specialist at C3.

Though ICE's actions to round up and detain suspected illegal immigrants has attracted fierce criticism, its efforts to combat Internet child abuse has won praise.

"They have been really the front line with this effort," said Allen. "Ultimately what is at stake is the protection and the safety of the world's children."