Cassidy Wolf, 19, says a few months before she was crowned Miss Teen USA last year, a man took naked pictures of her.
He did it by taking control of the web camera on her computer.
Wolf is using her high profile position to teach others about online privacy protections.
"Change your passwords. Delete your browsing history. Every couple of weeks, delete your cookies. Put a sticker over your webcam. And just be extremely cautious about what you are doing online," Miss Teen Cassidy Wolf said.
To get her message across, Wolf is teaming up with SnoopWall. It's an app that lets you turn off settings on other apps that secretly activate features like the camera, GPS and Bluetooth to track smartphone users.