295w ago - Google engineers have adapted a software programme to help track child sex predators and search for patterns in images of abuse on the web.
Google created the technology for the National Centre for Missing and Exploited Children (NCMEC).
It was originally developed to block copyrighted videos on the company's YouTube division.
The programme uses pattern recognition to enable analysts to sort and identify files containing child sex abuse.
Google says its aim in teaming up with the centre's Technology Coalition Against Child Pornography is to develop solutions that would make it harder for people to use the web to exploit children or traffic in child pornography.
"You always hope that your work will eventually be used to do some good in the world, and this was an amazing chance to make that hope real," said Google research scientist Shumeet Baluja.
Mr Baluja, who was also the technical leader of the project, said that as more and more predators use the web to ensnare children, "analysts were getting overwhelmed by all of the data they had to sift through".
Since 2002 the NCMEC has pored over 13 million child sex abuse images and videos in an effort to help police identify and rescue children from harm.