THE world's three biggest secret paedophile websites, with potentially millions of users, were identified by the FBI as part of its investigation into Irishman Eric Eoin Marques.
Three sites called Lolita City, The Love Zone and Pedo Empire and containing huge numbers of images, including brutal rapes of children, were identified by the American law enforcement agency during its investigations.
The sickening websites cannot be accessed over the ordinary internet. Users download and use encryption software before paying for access.
US authorities are seeking to extradite Mr Marques, 28, to Maryland to face charges of distributing, conspiring to distribute and advertising child pornography as part of a major global investigation.
According to the FBI, the charges relate to images on a large number of websites that are described as extremely violent, graphic and depicting the rape and torture of children.
If convicted, Mr Marques, who was born in New York and moved to Ireland with his family at the age of five, will face up to 30 years behind bars.
He was arrested in Dublin, where he had run a web-hosting company from his apartment in Mountjoy Square for the past eight years.
After his arrest, online magazines reported that websites known to be used by paedophiles were shut down by their operators, who suspected they had been infiltrated by computer hackers believed to be working for US law enforcement.
It is understood the operators found that spyware or "malware" had been introduced into their secret websites that could potentially identify the operators and hundreds of thousands of users.
Mr Marques's father, Antonio, claimed his son was innocent of any involvement in facilitating paedophile pornography, saying he "did not allow it" on the Freedom Hosting site he is believed to have set up in 2008.
The FBI, in seeking his extradition, said he had transferred large sums of money to accounts in Romania.
Within hours of Mr Marques's arrest, underground internet users who employ specially encrypted networks to buy and sell drugs and other illicit goods and services – as well as sharing pornography – also began reporting that their systems had been compromised.
It is understood to have taken years for computer experts, mainly believed to be private contractors working for US agencies, to infiltrate the so-called Dark Net where vast numbers of people use secret programming to hide their identities on the net.
One of the biggest sites on "Tor" networks, as they are known, is Silk Road, said to be the biggest drugs supermarket in the world.
In order to infiltrate and expose the child pornography and potential terrorist use of encrypted websites on the internet, the US and Britain have been using "mass surveillance", as was revealed by American computer expert Edward Snowden.
Paedophiles have been using the internet since it became publicly available, and quickly began hiding their images in what were then called "private chat boxes".
However, these were identified and law enforcement agencies around the world, led by information supplied by the US, began making mass arrests in 2002 and 2003.
Several hundred men were identified as having accessed a paedophile pornography site called Landslide operated by a Texas couple.
The site and its operators were identified as a result of an investigation by computer experts working for the US Postal Service who passed on their findings to the FBI, who in turn alerted police forces around the world.
Most of those arrested had used their credit cards over the open internet to access the sites. Since then, paedophiles have begun using the highly sophisticated Dark Net systems to avoid detection, and arrests have dropped considerably
Online tech magazines have reported that it has taken the American authorities five years to uncover the facilitation networks hidden behind the encryption systems. They have also said the "anarchist" group Anonymous actually identified and exposed these hidden systems two years before the US authorities were able to do so.
Meanwhile, Minister for Communications Pat Rabbitte has called an "urgent" meeting with the three main internet suppliers in Ireland – Eircom, UPC and Vodafone – to discuss ways of blocking paedophile content on the internet. The meeting is expected to take place tomorrow.