"We have now reviewed almost 15 million images, five million last year alone, currently averaging about 200,000 a week," says Ernie Allen, the founder and president of the National Center for Missing and Exploited Children.
That's where the public and Internet companies like Google turn when they run into child pornography online.
Four Google engineers just spent a year developing a new tool to help the National Center for Missing and Exploited Children sift through the images in search of victims and predators.
"There's probably no company better suited to help us in this situation, and they were willing to do that," says Allen.
Google encourages its employees to devote 20 percent of their time on unassigned projects. This project will speed up a process that used to rely strictly on the human eye to recognize telltale aspects of the images.
"The technology enables us to identify unique features and then search against a vast database for other images containing that similar feature," says Allen.
Details of how it works is secret, along with how it helps to rescue children and prosecute predators. However, Google's director of public policy, Alan Davidson, is able to share this much.
"We sometimes call it the bedspread detector. This might be the ability to look at not necessarily a person in an image, but actually another feature in the room -- a bedspread, a photograph, something that's on a t-shirt and find duplicates of that," says Davidson.
Common characteristics can be important clues to help identify organized crime rings and lead to prosecution.
"What Google is doing is not just helping us prosecute more offenders. Google is helping us identify and rescue children and save their lives," says Allen.
Google is hopeful the collaboration with the National Center for Missing and Exploited Children will continue, and after Ernie Allen's visit to the Googleplex, a number of new ideas have been advanced.