Ashton Kutcher's voice started quivering during his emotional testimony at a US Senate hearing in Washington yesterday.
The actor is founder of a group called Thorn: Digital Defenders of Children, which builds software aimed at ending sex trafficking and child sex abuse.
He told the committee he's been on FBI raids and seen things "that no person should ever see".
(Some people may find the following content distressing.)
"I've seen video content of a child that's the same age as mine being raped by an American man who was a sex tourist in Cambodia. This child was so conditioned by her environment that she thought she was engaging in play."
Kutcher says the technology he "is building is efficient; works, it's nimble, because traffickers change their modus operandi, and we can as well just as efficiently."