Skip to content

Meet the Team: A Conversation with Dr. Rebecca Portnoff

October 28, 2023

4 Minute Read

They say it takes a village to raise a child. At Thorn we believe it also takes a village to protect one. Our staff community, full of the best hearts and minds from tech, child protection, business and nonprofit fields, creates powerful products and programs to defend children from sexual abuse.

We sat down to have a conversation with Dr. Rebecca Portnoff, Head of Data Science at Thorn, to learn more about her career and what working to defend children with technology is really like.Dr. Rebecca Portnoff

Q: What’s your background and expertise?

A: I received my BSE in computer science at Princeton. My undergraduate thesis at Princeton was focused on machine learning, specifically natural language processing. I then went to UC Berkeley to get my PhD in computer science, where I worked in the computer security and machine learning departments. My dissertation focused on building machine learning technology to combat child sexual abuse, and other illegal activities online. 

I’ve been working in the intersection of machine learning and combatting child sexual abuse for the last 10+ years. I’ve dedicated my entire career to this mission.

Q: What drew you to Thorn?

A: In the first year or two of my PhD program, I cold-called NGO’s, law enforcement officers – really anyone who would talk to me – and asked how technology could support them better. I learned a lot through these conversations about the incredible child safety ecosystem that already exists, and the many ways child sexual abuse manifests. I turned these conversations into my PhD dissertation: building technology to combat child sexual abuse.

It was through these conversations that I got connected to Thorn. 

Towards the end of my PhD, I had a conversation with a LE partner, where I asked him where he thought a computer scientist working in this issue space could have the most impact. He immediately answered, “Thorn. There’s nowhere else like Thorn.” Seven years later, the answer to that question – where can a computer scientist have the most impact working on this issue – is still the same: Thorn. That’s why I’m here.

Q: What do you appreciate most about the impact Thorn makes?

A: It’s easy to become angry when working in this space. Seeing the scale of abuse that is occurring, and the devastating harms that come to each child as a result of these tremendous betrayals, is heartbreaking. The counter to that, is hearing the stories of healing and hope that come after recovery.

Q: What do you wish people knew about this issue space?

A: I wish people knew that this isn’t a niche issue, and this isn’t an overblown issue. If we look at just the United States, the CDC reports that approximately 1 in 4 girls and 1 in 13 boys experience child sexual abuse. 91% of abuse is perpetrated by someone known and trusted by the child or the child’s family members.

What that means is that almost every family, group or institution you are in will have struggled with this issue. A child in your community has suffered this abuse; an adult in your community has betrayed a child by abusing them. The decisions that are made in your community to either protect the child or cover up the harms the abuser has perpetrated will have real life consequences, and these consequences will spread out to the rest of your community.

I want people to know this not because I want people to live in fear, but because I want people to live with compassion, kindness and responsibility. The choices you make, the words you speak, have an impact. When something this painful is brought to your attention, you have a choice: to look away, or to ask – how can I help? Each of us will have opportunities, whatever our line of work or walk in life is, to make that choice, to choose to help.

For more inspiring employee stories, see our “Life at Thorn” collection.

Stay up to date

Want Thorn articles and news delivered directly to your inbox? Subscribe to our newsletter.