IT may sound horrific, but it was just another day at the office last week when Detective Sergeant James Traynor spotted the computer image of a child being sexually exploited.
Traynor, a 38-year-old Glaswegian, heads up the victim identification team at the National Crime Agency's Child Exploitation and Online Protection Centre.
He works out of an office block in south London, but by the end of the week, police in New York had arrested a suspect and the child in the image was safe.
Over the years, the painstaking work done by the small unit - often working from the most minute of clues in order to establish where the abuse took place - has meant that some 208 child victims are no longer at risk.
Traynor and his three colleagues monitor huge numbers of images containing scenes of child sex abuse in order to work out where the child might be, and who the abuser is. Often it can be a simple clue, like the type of watch the offender is wearing, or a distinctive picture on a wall.
"Last week," said Traynor, "we were looking at a [paedophile] website which we had already infiltrated and saw some images which had been posted. The abuse contained within them was at the lower end of level one - images depicting erotic posing but with no sexual activity.
"The background led us to suspect that the images were from America. Within 72 hours of the images being posted we had sent them to America, and within another 72 hours, New York police had arrested an alleged offender and safeguarded the child."
The success of such operations is testimony to the national and international co-operation that the identification team enjoys in its quest to bring to justice those who perpetrate child sexual abuse, and those who view its images.
The CEOP command talks of the "increasing globalisation of child sexual abuse". But to counter this, Traynor can call on rapid assistance from colleagues in 40 countries across the world.
"There is a tight-knit community of international law enforcement specialists whom I can access when required," he says. "These relationships allow us to provide quick-time support, advice and guidance that can ultimately help safeguard a child from abuse."
CEOP was set up in 2006 and since last October it has been part of the National Crime Agency.
Last year, it received almost 19,000 reports relating to the sexual exploitation of children - a rise of 14% on the previous year. Sixteen per cent came via a "Click CEOP" app, which can now be found on some 1700 websites such as Facebook.
CEOP command also distributed more than 2866 intelligence reports to UK and overseas agencies last year about individuals suspected of being involved in abuse. As a result, 192 suspects were arrested and 790 children rescued.
It tracks registered offenders who have failed to comply with notification requirements under the Sexual Offences Act 2003, and also focuses on organised criminals who profit from the distribution of child abuse images.
Traynor, in addition to running the victim ID team, is also CEOP command's Scottish police liaison officer. He keeps in close contact with Police Scotland, providing training to detectives, child-protection investigators and specialist online investigators.
Of the ID team, he says: "We liaise with the UK's 43 police forces and co-ordinate the response of the British police forces towards identifying children contained within indecent images.
"We work hand in hand with specialist units in every force in the UK. We're on first-name terms with most of them and we're safe in the knowledge that we can trust them.
"If we make a phone call at 5pm on a Friday, they will be out, and through the suspect's door, by 6pm. The relationship works both ways - if they come to me with a problem, they know I won't stop until it is solved."
The job can be extraordinarily painstaking. Seemingly trivial pieces of information can yield vital clues if Traynor "worries away at it" for long enough. His instincts have been honed by years in detective work.
In one case, he spotted part of a canoe in the background of some images of abuse. His researches led him first to a boating magazine, then to the canoe manufacturer, and ultimately to where the canoe was sold. Police later arrested a man, who was subsequently given 14 years in prison.
"We analyse every image that we are sent," he says. "Currently we have two million indecent images of children on a database. They have been analysed to find the clues contained within in order to identify the victims. We use specialist software so that we don't need to analyse the same image twice."
He talks in detail about one particular operation. "My team analysed images that were shared online in specialist paedophile websites. Access to them was via passwords. You had to go through various levels of security in order to get the people on the sites to trust you.
"Working with partners across the globe, including police forces from Germany and Denmark, we infiltrated the sites and targeted those who abused children for the sexual gratification of others on the site.
"There was a series of images being distributed which we realised had been made in the UK. The person who took them had used all available methods to hide the identity of the victim and the offender, and the location.
"As a result of continually monitoring the group and analysing the images as they became available, we made arrests all over the world.
"We arrested a man in Indonesia who was involved in the group. We arrested others in Germany and Denmark, and every time someone was arrested, we looked at the clues contained within their computers, and at the detail of their police interviews, to help us identify the location of the child.
"We widened our net and tried to find specialists in their field to help us crack the methods the group was using to encrypt their data.
"We worked on the case for 18 months, and saw that child grow, but also saw that the abuse was continuing. We used technology to identify the location, and within a couple of hours of our telling the police in Liverpool, they had a team of officers at his door. He was arrested while online."
Three children were safeguarded; the man was jailed for eight years and his partner got four.
Prior to joining the police in 1999, Traynor, who is married with a five-year-old son, worked with Royal Mail, rising to become a sales executive.
"At 24 I had the car, the corporate credit card, everything, but I had always wanted to be a police officer," he says. "It was in my heart."
He joined Kent Police as a front-line officer and in 2001 he became part of a tactical CID unit. He and a colleague later launched an arrest team to apprehend elusive criminals.
By January 2006 he had become a child-abuse investigator in Kent. His successes included a 2009 case in which a man was jailed for four years for a string of offences involving indecent images. "I realised that protecting vulnerable children was what I really wanted to do," he said. "It was the chance for me to make a real difference."
As for the possible consequences of having to view so many distressing images, Traynor and his colleagues undergo counselling every three months but can seek extra help if needed.
"When I'm out and about, and I see someone taking photographs, I look around to see whether the pictures are overt or covert," he says. "I think I'm quite protective of my son, where he goes and what he does, but I continually remind myself that the people we're dealing with are only a minute element of society. I don't let it take over my life. I do lead a healthy, normal life."
The CEOP command has had considerable success with its educational project Thinkuknow. There are some concerns, however, that many young people might be vulnerable to abuse because of personal issues like low self-esteem or social isolation.
But Traynor says decisively: "I don't think we should be pointing the finger at any child ... because they might be seen to put themselves in risky situations.
"Remember, we are the adults - they are the children. We are here to protect them until they reach adulthood.
"Adult sexual interest in children is the reason why certain things happen. It has nothing to do with the child."
Anyone wishing to report any concerns to CEOP command can do so via the Click CEOP button available via www.ceop.police.uk. Concerns over child abuse images/websites online can also be reported to the Internet Watch Foundation via its website at www.iwf.org.uk