Traditional policing techniques rather than technology led to the discovery of a series of closed groups on social networks that were being used to distribute child sexual abuse pictures.
The discovery by the Department of Internal Affairs’ Censorship Compliance Unit in October 2010 led to an international criminal investigation, dubbed Operation Laminar, which targeted 55 individuals in 20 countries suspected of distributing of child sexual abuse pictures. The DIA said in a media statement that some of the suspects were involved in the abuse of the children depicted and that most of the suspects are now in prison or facing prosecution. At least 12 of the children being abused, including one in New Zealand, have been identified and have since been removed from harm.
Steve O’Brien, national manager for Censorship Compliance, told Computerworld that many of his team had gained considerable experience working in this field and some had been with the unit since it was formed in 1996. Consequently they had become “very good at spotting anything new,” he said.
O’Brien said the initial stages of the investigation had involved infiltrating and gaining acceptance on the groups, then alerting and providing the evidence gathered to international law enforcement agencies.
“It was ordinary policing techniques. There wasn’t really much technology involved.”
DIA general manager of regulatory compliance operations, Maarten Quivooy, said in a statement that the Department provided evidence of the illegal activities to 20 countries and worked with the Child Exploitation Investigations Unit of the US Immigration and Customs Enforcement service and Interpol.
The social networks being used by the suspects included Facebook (based in Menlo Park, California); Socialgo, (London, United Kingdom) and Grou.ps, (Palo Alto, California and Istanbul, Turkey).
The 20 countries with identified targets were: Australia, Bosnia, Brazil, Chile, Costa Rica, Finland, France, Germany, Indonesia, Italy, Mexico, Norway, Saudi Arabia, South Africa, The Netherlands, Tunisia, Turkey, United Kingdom, United States and Venezuela.
O’Brien said that his unit had relied on overseas authorities to inform the social networks concerned.
Earlier this year, Internal Affairs minister Amy Adams announced the Censorship Compliance Unit was one of the first agencies in the world to use Microsoft’s PhotoDNA software to identify images of child sex abuse.
According to Microsoft, the DIA is one of only two law enforcement agencies which had licensed PhotoDNA source code, the other is the Netherlands Forensics Institute. and the New Zealand Department of Internal Affairs have licensed the PhotoDNA source code.
PhotoDNA works by creating a unique hash tag that can be used to identify an image, in a similar way to how some anti-virus software works. These signatures can then be used to find matching illegal images on systems without the need for law enforcement officers to view them.
O’Brien said that PhotoDNA, and databases of known illegal images maintained by agencies such as Interpol, “greatly assisted” his team’s work but a lot of evidence gathering still depended on manual methods.
“By studying the background of a image for example, we might be able to identify a particular wall socket or a type of furniture, which could tell us which country it was taken in. These little pieces of information can help to build up the whole picture.”